The Hoya Corona Part I

By Dale Kloppenburg Dale Kloppenburg 6427 N. Fruit Ave. Fresno California All rights reserved © 15 July 2003 Updated Nov 2007 Revised August 2009 Updated August 2010

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The Hoya corona: Corona in Latin means a garland, wreath or crown. It is a fleshy structure that occupies the center of the flower. This structure results from the congenital union of the stamens (5). Evolutionary steps leading to the Genus Hoya (AsclepiadaceaeAsclepiadoideae) progressed to complexity from the more simple flower forms found in Apocinaceae-Plumerioideae, where the anthers are still free from the style head. In a simple flower we have slender filaments topped by anthers (containing the pollen). The corona is initiated after the corolla has partially developed. The 5 coronal scales are really very complex, as we will see. They are fleshy, glabrous, are attached (form a continuity) with the column and the edges of the stylar table that occupies the center of the hoya flower. On this lower inner surface of each coronal scale there is a triangular membranous structure the anther which has two pockets that hold the pollinia (pollen). (See picture below) Lets look at this structure in picture form. The corona with all of its variables makes an excellent taxonomic tool to delineate hoya species but in some old descriptions it is not even mentioned. This is a top view of a corona above the corolla. There are 5 scales (lobes) here (coronal scales). Each is fleshy, glabrous with an inner and outer apex and here we are viewing a flat dorsal surface. The inner lobes almost touch in the center but not quite, each apex looks like it has been squeezed and is narrow. This is termed dentate* (like a canine tooth). The outer apex is rounded (obtuse) here with a slight sharp end (apiculate) The top (dorsal) is flat with a hump running down the center from apex to apex. Inner apex

Outer apex

Dorsal surface

*The inner lobes are of two main types dentate (narrow on top with some depth vertically) as above or flat, termed spatulate (wider on top and narrow in depth). There are some intermediate types that are nearly round tapered structures. The inner lobes very in length in the different hoya species. The coronal scales can be of different shapes and sizes in the different species. The center may be raised and the scale slop down toward the outer apex or the dorsal may be sway backed, with both ends higher than the middle. Widths, depths, textures and colors of the corona exhibit a lot of variation.

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Below is a picture of a crown removed from the corolla to show its under surface:

Central column

This is a bottom view of a corona. In many hoya species (not all) the edges of each coronal scale turn under and are rolled inward to form a channel (most often referred to as a groove and sometimes as sulcate). The edges of the scale mostly touch each other and there is a hollow formed on each side. These edges, as here, may only come in slightly from where the adjacent scales meet (the sinus and where the anther wings are located) or may extend into the central column. The edges of the scale here have fine parallel groves (sulcations). Finely sulcate surface

Central channel or groove Anther wing A side view of a corona removed from the corolla. Note that the scales have depth and length and vary with the different species. This species has a distinct column so is rises above the corolla slightly. It is in this column that the ovaries are housed. Coronal channel or groove Outer coronal lobe apex Column, the flared lower portion is where it was affixed to the corolla

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A photo enlarged of the underside of an anther showing the two pockets, which hold pollinia. The top (other side) of the anther is attached in its central area to the bottom of the coronal lobe near the base of the inner apex. The anther is triangular and membranous. The lower edge of the anther is attached along one of the edges of the pentagonal stylar table. The table of course is covered by the coronal scales (especially the inner lobe) and the anthers, so is not directly visible when you look at a flower.

Corona of a Hoya Flower

Coronal scale

Anther wings, sides forming the channel to the stigmatic receptive area. Anthers (5) meeting in center. Retinaculum Inner lobe of coronal scale.

Outer lobe of coronal scale.

Photo of hoya flower crown (corona). A top view magnified approximately 15 times.

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Hoya acicularis Green 2002

Top view of the corona and corolla enlarged about 8X. Scale size is broadly diamond shaped with broad bilobed extensions. The inner coronal lobe is spatulate, outer broadly acute. The scales exceed the corolla sinus. Corolla inside is densely pubescent except for the apex which is glabrous, Outside glabrous.

Skewed bottom view of the corona enlarged about 16X showing the sulcate flat bottomed bilobes forming a groove below clear to the thickened (dark red) hirsute column.

View of the corona enlarged about 16X showing the longitudinal sulcation of the coronal bilobes curving around the blunt outer apex of the lobe and meeting at the end. The bilobes begin well up the side of the scale. The anther slot curves to the under side of the scale. The dorsal portion of the scale has a slight keel down the center.

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Corona: 5 lobed, glabrous, upright with long bilobes, inner apex spatulate, long and narrow; outer apex obtuse. Top nearly flat with slight keel and finely sulcate, especially the bilobes (longitudinally). Scale does not reach the corolla sinus. Scale, broadly diamond shaped. Collar thick 0.10 cm. tall. Apex to apex Apex to center Apex to outer end Retinaculum to ret. Ret. to center Ret. to aw. Anther wing to aw.

0.24 cm. 0.26 cm. 0.29 cm. 0.19 cm. 0.10 cm. 0.12 cm. 0.16 cm.

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Hoya acuta Haworth 1821 I now believe this sp. is H. rumphii King & Gamble 1903

Corona bottom view enlarged about 16X. Channeled from outer apex to inward from thew anther wings, inner ends rounded; sides overlapping slightly. Anther wings are narrow and protrude a little. Outer apex of coronal lobes are sharply acute. Side lobes finely sulcate.

Top view of the corona enlarged about 16X. Inner lobe is medium long dentate but does not reach the center. Crown is somewhat flat with the outer lobes raised a little. Dorsal is slightly cupped with sharp edges and a rudimentary umbo in the central region. Apex - apex Apex - center Widest Ret. - ret. Ret - center Aw. - aw. Aw. - center

0.36 cm. 0.40 cm. 0.18 cm. 0.12 cm. 0.10 cm. 0.25 cm. 0.20 cm.

Side view of a coronal scale enlarged about 16X. Inner lobe is dentate, exceeded by the membranous triangular anther (not shown here). Dorsal is concave slightly with a raised center. Outer lobe is actually raised above the inner lobes is narrowly rounded sides with acute apex. Anther wings are deeply scythe shaped.

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Hoya albiflora Zipp. ex Blume 1848

Top view of the corona enlarged about 16X. The sectional character of the sway backed corona is evident. Inner lobe is spatulate but not they typical shape found in the Acanthostemma species, it rises up sharply but does not exceed or cover the anthers. Anthers meet neatly in the center, the dark retinacula are very visible. The scales are very broad just out from the inner lobe, possess narrow bilobes projections along the under sides that meet at the apex to form a emarginate end. Outer lobe obtuse apex reflexed. Corona: Apex - apex 0.45 Apex - center 0.55 Widest 0.33 Ret. - ret. 0.17 Ret - C 0.20 Aw. - aw. 0.38 Ret. - aw. 0.24 Column 0.15 cm. tall widest opening 0.26 cm. Stylar crown: capitate 0.22 cm. tall.

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Bottom view of the corona enlarged about 16X. The bottom here is tightly channeled and the surface is very finely sulcate. The apical area is pressed in, bilobes are visible forming an intricate apical area. The anther wings protrude and are narrowly double. The column is very thick and relatively large.

Side view of a coronal scale enlarged about 16X. The anther is shown rising above and loose apically from the inner lobe. Inner lobe apical areas not attached to the anther which extends downward to form the rounded anther wing. You can see there is a ridge in the top center of the outer part of the scale, the narrow bi lobed ridges arise from the bottom area and extends toward the outer apex.

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Hoya aldrichii Hemsley 1890 Inside view of a flower enlarged about 8X. Corolla inside is pubescent. Corona is horizontal, glabrous and finely sulcate. Sinus – sinus 0.37 cm. Sinus – center 0.35 cm. Sinus – apex 0.60 cm. Apex – center 0.75 cm. Widest 0.48 cm.

Bottom view of the corona enlarged about 8X. The lobes are channeled to the central column, rolled edges are sulcate, glabrous, outer apex is acute, broadest near the middle. Collar short and thick walled.

Top view of the corona, inner lobe is dentate, do not reach the center, dorsal is slightly concave with a noticeable umbo forward, outer apex is acute and exceeds the corolla sinus. Apex – apex 0.36 cm. Apex – center 0.40 cm. Widest 0.22 cm. Ret. - ret. 0.09 cm. Ret. – center 0.06 cm. Aw. – aw. 0.20 cm. Aw. – center 0.15 cm. The anther wings and retinacular area are sunken below the scale dorsal surface. Side view of a scale enlarged about 32X. lobe is horizontal, note umbo near inner apex. Anther here bent down in abnormal position.

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Hoya amrita Kloppenburg, Siar & Ferreras 2010

Corona: inner lobes dentate with sharp keel all the way to outer apex that slopes slightly down, fine linear sulcate, lobes widest at the base, sepals slightly creped and below the inner apex, channeled below to roll of the anther wings, no overlap of edges, diagonally sulcate, a few hair cells in channel to the central collar. Anther wings extend beyond sides. Enlarged about 12X. Apex – apex Apex – center Ret. – ret. Ret. – center Aw. – aw. Aw. – center

0.57 cm. 0.60 cm. 0.14 cm. 0.12 cm. 0.26 cm. 0.26 cm.

Side view, bottom view and top view of coronal scale enlarged about 8X.

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Hoya andalensis Kloppenburg 2005

Top view of the corolla and corona enlarged about 16X. The outer surface of the corolla is glabrous. The lobes of the corona just reach the sinuses of the corolla. The inner coronal lobe is yellow, difficult to see and granulose above. Outer lobe is bifid and fleshy, glabrous.

Bottom view of a corona enlarged about 16X. The central column is thickened and prominent. Bilobes form a channel that nearly reaches the column, the surface is finely sulcate. The anther wings are well developed and extended slightly, all surfaces are glabrous.

Anther wing area below, greatly enlarged to show the unusual protrusion on this surface view. Diagonal sulcations on the lower bilobes forming the sides of the channel are visible especially on the left lobe. Again the center column is prominent.

Top view of the corona enlarged about 16X. The inner lobes do not reach the center, anthers are exposed, membranous and triangular. Inner lobe is 0.04 cm. long and almost distinct from the rest of the scale. Lobe is oval and rounded 0.13 cm. long red in color. Apex - outer ends 0.20 cm. Widest 0.07 cm. Overall width including bilobes 0.10 cm.

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Outer bilobes are rounded on sides but cleaved inwardly on the inner flat surface. Anther wings well developed and deep. A much enlarged view of the corona dorsal surface. Note that the yellow inner lobes are difficult to distinguish. The upper flat surface of the bilobes are longitudinally sulcate but the lobe itself is not. Anther wings are membranous and meet in the center as triangles. Retinacula and pollinia are visible.

Here another photo showing the top view of the protruding anther wings and the sulcate bilobes and full rounder central coronal scales. Ret.- ret Ret - center Aw. - aw. Aw. - center

0.07 cm. 0.07 cm. 0.18 cm. 0.17 cm.

Stylar crown greatly enlarged. It is in the upper center (bright object) it has a short filamentous head. to the left and right are the pulled back anthers and below to each side the coronal scales. This is really a beautiful distinct small flower.

Greatly enlarged side view of a scale. As you can see the inner lobe is almost distinct from the rest of the scale. The triangular anther wing overtops the inner lobe. Outer bilobes have rounded outer surfaces. I wish I had the space to display all 75 photos of this flower.

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Hoya anncajanoae Kloppenburg & Siar 2007

Bottom view of the corona, lobes are channeled, finely sulcate, edged full and rounded. channeled only to the sinus area, center here with ovaries still in place. Anther wings barely protruding, surfaces glabrous except some hair cells where corolla attaches. Enlarged about 16X Apex – apex Apex – center Center – end Widest

0.28 cm. 0.31 cm. 0.35 cm. 0.13 cm.

Top view of the corona, inner lobes are long spatulate and overtop the anthers, outer lobes taper to a narrow obtuse end between the bi-lobes, dorsal is slightly concave. bi-lobes are shelf like and meet at the outer apices on their vertical ends their surfaces are finely sulcate. Enlarged about 16X. Ret. – ret Ret . – center Aw. – aw. Aw. – center

0.10 cm. 0.10 cm. 0.23 cm. 0.23 cm.

Picture of an individual scale top view, showing the long tapering inner lobe the sulcate dorsal with a very slight keel down the center, apical end submerged between the two rather wide and flat topped bi-lobes with strongly sulcate upper surface. Enlarged about 32X.

Side view of a individual coronal scale, long inner spatulate lobe overtopping the clear membranous anthers to the upper right, scale is relatively thick, anther wings are cupped but not scythe shaped. Pollinarium showing as yellow area below the anther. Enlarged about 16X

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Stylar crown. rather capitate with a loose lobed surface, glabrous and damp on a columnar raise. There is considerable variation in stylar crowns in hoya species.

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Hoya antimonensis Kloppenburg & Siar 2006

Bottom view of the corona enlarged about 16X, lobes are full and channeled but not to the central column that is 0.05 cm. tall, sides are diagonally finely sulcate, lobe apex is blunt, all surfaces are glabrous and waxy.

Top view of the flower, coronal lobes reach the corolla sinuses. inner lobes are dentate and nearly touch in the center. Surfaces are waxy glabrous, dorsal surface is horizontal, slightly concave with a medial low ridge from inner lobe to apex. Retinacula in some flowers hidden by the lobes above, Anther wing is thick and squared off at the apex.

Corona top view. Apex – apex Widest Ret. – ret. Ret. – center Aw. – aw. Aw. – center

0.40 cm. 0.19 cm. 0.07 cm. 0.07 cm. 0.20 cm. 0.17 cm.

Side view of a coronal scale, There is a rounded shelf along the lower surface that extends to the outer apex. When this type pf scale dries a little the apex splits and Blume referred to this as a emarginate apex. The anther wings are deeply scythe shaped.

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Hoya apiculata Scheffler 1976 Species incorrect

Lower side of the corona enlarged about 8X. The scales are shortly channeled by the curvature of the side lobes with sulcate surfaces. There is a central column, 0.07 cm. tall and with the largest diameter being 0.12 cm. Top view of the corona enlarged about 8X. Side lobes can be extending under scales outer apex forming a cleft at their outer apices. Note again here how swollen the pollinia are and how thick the anther wings are. Apex – apex Apex – center Widest Aw. – aw. Ret. – ret. Ret. – center

0.25 cm. 0.30 cm. 0.18 cm. 0.23 cm. 0.11 cm. 0.11 cm.

End view of the corona enlarged about 8X. Note the central portion is raised but so are the outer apices. The dorsal surface is cupped (concave) and scale edges are rounded. Apices of coronal lobes are always opposite the corolla sinuses and here the sinus area forms a trough and curves down slightly. Coronal lobe sides taper inward to where the narrow side lobes wrap around from the lower sides.

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Individual coronal scale side view enlarged about 16X. Anther exceeds the inner lobe, which is raised in the center and is narrowly spatulate, slightly concave on the lower side. Dorsal surface of scale is concave also with the edges rounded. Anther wing is deeply scythe shaped. A pollinium is still hanging in the anther pocket and is plump. Material to the right is column tissue.

Stylar table of the corona enlarged about 8X. Three scales have been removed. The pentagonal table rises in the center like a volcano with a hollow indentation in the center. Most all styles are raised in the center and have different configurations, some are capitate in varying degrees some with sharp apices and many are mealy in texture. This is the only one I have found that is volcano-like. Note on the corners above where the stigmatic receptive area is, that these points are slit and on the surface is a raised template of the Retinaculum to be secreted there by the stigmatic fluids.

I am not sure this specimen is the true species since the description says corolla outside glabrous and this one is definitely more pubescent there than inside, nor is it lanceolate, acute, rather it is broad and apiculate. In addition the stigma (stylar crown) is said to be apiculate, not so here.

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Hoya apoensis Kloppenburg & Siar 2011

Top view of a flower enlarged about 8X. Corolla is pubescent except for the apical ends of the corolla lobes. Corona is bilobed and raised in center. Inner lobes on some flowers touch others are a little short. Anther wings are plump rounded and surfaces are sulcate.

Corona lower surface enlarged about 16X. Surfaces are glabrous, lobe surfaces are finely sulcate. Lobes channeled only to the sinus area with edges rounded and rolled under, central area sunken with ridges from the central column to the sinus areas under the anther wing outer apices. Bilobed outer apices obtuse.

Top view of a corona enlarged as above. Inner lobes are elevated, round, dorsal rounded ending abruptly between the two extended bilobes. Bilobes have outer apices that touch at and are rounded. Apex – apex Apex – end Apex – center Widest dorsal Ret. – ret. Ret – center Aw. – aw. Aw. – center

0.22 cm. 0.29 cm. 0.24 cm. 0.13 cm. 0.08 cm. 0.08 cm. 0.22 cm. 0.22 cm.

Anther wing ends are obtusely rounded as are the bi-lobe ends.

Side view of a coronal scale. Inner lobe moderately long, raised, rounded, dorsal area short ending in a outer lobe that descends slightly diagonally between the two lower rounded surfaced bi-lobes. Anthers attached well down below inner lobe.

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Hoya apoensis var. sigittaria Kloppenburg & Siar 2013

Corona: bilobed, inner lobe narrow spatulate, outer lobe obtuse, bilobes flat near lobes and bending inward and touching at outer apex with rounded ends, sulcate. Channeled below narrow with large open center and thickening of short central column, hair cells around column base. Enlarged about 13X. Apex – apex Apex – center Center – bilobes Bilobe extensions Ret. – ret. Ret. – center Aw. – aw. Aw. – center

0.18 cm 0.20 cm 0.23 cm

0.06 cm 0.06 cm 0.06 cm 0.16 cm 0.15 cm Enlarged about 14X. Left bottom view of the corona; below dorsal view of the corona

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Hoya archboldiana Norman 1937

Top view of a single coronal lobe. Note: the length here enlarged approximately 16 times. This outer lobe actually follows the contour of the cupped corolla, See the flower picture on the first page. Also see the indent on the outer apex which results from the meeting of the lower projections along the bottom of the lobe.

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Bottom view of the same coronal lobe as on the previous page, same magnification (a better photo). Here the grove formed by the curving sides of the lobe is clearly visible. The bulbous apical area and the indentation in its apex are shown, the surface is essentially glabrous although slightly rough.

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Side view of the apical portion of the corona enlarged approximately 16 times. Here, note that the inner lobes are spatulate and do not reach the flower center, so the anthers are exposed. The crown is decidedly dome shaped, the dark retinacula is readily visible and the yellow anther wings forming the channel.

Top view of the corona again at 16X. Note how the inner lobe seems a little structurally different then the main lobe and is spatulate, it curves over at the center but still leaves the anthers exposed.

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Hoya arnottiana Wight 1834

Bottom view of the corona enlarged about 16X. Sides curl under to form the groove, this surface is finely sulcate, narrow side lobes along the lower side surfaces meet before reaching the outer apex to form a little “ear”, the apex is acute. The center is thick forming a short column. The anther wings are linear, narrow and protrude slightly.

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Top view of the corona, enlarged about 16X. Scales fairly widely spaced, Outer apex acute exceeds the corolla sinus; central portion broad and slightly concave. Inner apex although described as short is not near as short as in Hoya serpens Hooker, it is dentate and does not reach the center. Side shelves arise at the widest portion of the scales along the lower side and almost reach the apex. Anthers, retinaculum and linear narrow anther grove (wings) visible.

Side view of the coronal scale enlarged about 16X. The outer apex is raised above the inner. Note the outer apex turns down, the inner apex is hard to distinguish here but is much shorter then the projecting anther; here with a pollinarium attached, the 2 pollinia visible. The scale is rather thick, vertically. Anther wings are deeply scythe shaped.

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Hoya attenuata Christophersen 1935

Top view of the corona showing the very prominent anther wings. Note the narrow scales. Apex - apex Apex - center Widest Anther win - aw. Retinaculum - ret.

0.33 cm. 0.33 cm. 0.10 cm. 0.14 cm. 0.07 cm.

Corona bottom view enlarged about 8X. Scales are channeled, to the central column, and narrow, anther wigs protruding here are doubled and thick walled.

Side view of a coronal scale enlarged about 16X. Inner lobe is raised dorsal relatively horizontal apex obtuse. Anther wings are thick and scythe shaped. The scale is not very deep.

Top view of the corona with the central stylar area exposed, enlarged about 16X. The edges of the pentagonal table here are rounded and striate on the upper surface, this hides the retinaculum and the pollinia were also difficult to extract because of this structure. The raised center here shows up as a yellow spot. I believe the retinacula are actually formed under the stylar table and the way the anther wings protrude under this structure would indicate this.

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Hoya aurantiaca Kloppenburg, Siar& Cajano 2009

Inside view of the flower with corona enlarged about 8X. .The coronal lobe apices reach the corolla sinuses are totally glabrous. The corolla surface inside is finely granulose to extremely fine puberulent.

Bottom view of the corona enlarged about 8X. Outer lobes are upright, channeled bellow all the way to the column.. glabrous with all exposed surfaces sulcate, There is a central column not evident here that is 0.10 cm. tall with opening 0.12 cm. oval shaped.

Dorsal view of a coronal lobe enlarged about 16X. The inner lobes touch in the center or nearly so ate dentate almost knife like, dorsal surface is concave with sharp edges the center is raised from apex to apex, outer apex is acute. Apex – apex Widest Ret. – ret. Aw. – aw. Aw. – center

0.30 cm. 0.15 cm. 0.04 cm same distance to center. 0.08 cm. 0.10 cm.

Side view of a coronal scale enlarged about 32X. Outer lobe is raised, here inner lobe not well defined is dentate, knife like exceeding the membranous anther. The anther wing is deeply scythe shaped.

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Hoya australis from Tafeta, Tutuila, Samoa Collected 9/23/03

Bottom view of the corona enlarged about 8X. The lower lobes are channeled in the center and seen from a side view as the outer scales are raised apically. In the center is a column 0.08 cm. tall 0.05 cm. above the corolla. Anther wings protrude a little.

Top view of the corona in the flower enlarged about 8X. The inner lobes are long spatulate and do not reach the center. The outer lobes are broadly obtuse, they do not reach the corolla sinuses. The dorsal in slightly concave. Apex - apex Apex - center Widest Ret. - ret. Ret. - center Aw. - aw Aw. - center

0.26 cm. 0.31 cm. 0.20 cm. 0.10 cm. 0.10 cm. 0.21 cm. 0.21 cm.

Side view of a coronal scale enlarged at least 16X. The anthers (to the upper right) are relatively fleshy and there is a pollinia still in the anther pocket (dark area). Inner spatulate coronal lobe just peeking above the anther. Dorsal concave with rounder edges with outer apex raised. The anther wings are deep but more angular than scythe shaped which is seen in may hoya species.

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Hoya australis subsp. australis Robert Brown ex Trail 1830

Top view of the flower enlarged about 8X. Corona scale outer apex does not reach the sinus. Inner lobes short, dentate, not reaching the center where the anthers are well exposed. Dorsal cupped with an umbo; outer apex obtuse. Flower has a clean fragrance but is not strong, color white with rose markings under and around corona on the corolla. Clear honeydew.

End view of the corona (left) and bottom view (right) enlarged about 8X. The center is raised, dorsal is cupped and the outer apex curves down slightly. Below the scales are channeled, central collar is 0.05 cm. tall. Note that the sides of the scale are squeezed (narrower) below the dorsal portion. The stylar head (not shown here) is domed the same as in Hoya rupicola Hill. (see that folder for comparisons). Apex to apex widest Apex to center Ret. to center

0.30 cm. 0.28 cm. 0.35 cm. so the diameter is 0.70 cm. 0.13 cm.

Side view of a scale enlarged about 8X. The variations here are within a reasonable degree of variation. Differences are in size and the inner lobes are not as raised and the outer lobe does not curve over as much.

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Hoya australis subsp. nathaliae Kloppenburg & Siar 2012

Bottom view of the corona enlarged about 16X. Lobes are channeled to near the column and edges are sulcate inner edges rounded. Central column prominent 0.05 cm. tall. Channel begins a little in from outer apex.

Top view of the corona as above, outer apex broadly obtuse, inner lobes long sub-spatulate, glabrous and finely sulcate, dorsal concave with a central ridge. Inner and outer apices both raised. Anthers exceeding in the center. Apex – apex Apex – center Widest

0.34 cm. 0.38 cm. 0.21 cm.

Side view of the coronal scale enlarged about 32X. Here the scale is a little dried so not as flat as normal. The scale is thick and edged plump and rounded,. the anther wing is deeply scythe shaped with thick edges but not doubled. Central ridge of dorsal surface is visible here. Inner lobe does not exceed the membranous anthers.

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Hoya australis subspecies rupicola Forster & Liddle

Top view of the corona and corolla enlarged about 8X. The lobes do not nearly reach the corolla sinuses. Inner lobes are short, raised, rounded dentate with the anthers well exposed. Dorsal surface cupped at base of inner lobe with raised edges and outwardly to the emarginate obtuse outer apex. Apex - apex 0.23 cm. widest 0.17cm.

Apex to apex 0.23 cm. Widest 0.17 cm. Column base to outer apex 0.34 cm. Apex to center 0.29 cm. so the crown diameter is 0.58 cm.

Bottom view of the corona enlarged about 8X. The edges are rolled under but only a very short groove is formed. There is a large central column, 0.15 cm in diameter and 0.10 cm. tall. Color white except some red tones on collar base.

Stylar crown is well formed columnar dome here enlarged about 8X. Sides are not slick but top dome is more smooth. The large conspicuous membranous anthers are here folded back and some coronal scales have been removed. All white except the anther pockets are yellow.

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Side view of a coronal scale enlarged about 16X. Note the raised dentate inner coronal lobe, the sunken dorsal cup just back from the inner lobe and the rounded emarginate outer apex. Most noticeable is the extreme depth to the scales. Surface waxy and all white.

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Hoya bella Hooker 1848

Hoya bella hooker “An Amethyst set in Frosted Silver” Flower parts:

Top view of flower enlarged approx. 16 X.

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Note: the coronal lobes do not extend to the corolla sinus. The scales are blocky unlike Hoya lanceolata Hooker, which has sloping coronal lobes (pagoda roof shaped). The outer lobes are indented due to side lobes extending low down on the scale sides and curving up to form the apex. The inner lobes are spatulate, do not meet in the center so the anthers are plainly visible.

Bottom view of corona enlarged approx. 16 X. Here note: The bottom ridge extending from the collar base to the apex of each lobe. The hirsuteness around the collar. The very distinctive structure of the anther wings (walls doubled). The channeled outer lobe apex is indented (marginate). Side view of coronal scale enlarged approx. 16 X. Note: The inner lobe is spatulate. Hoyas can be divided into two groups based on the inner lobe shape, they are either flattened (spatulate) or pinched on the sides (dentate). The anther extends beyond the inner apex. The anther wing forming one side of the anther groove is rather prominent (deeply scythe shaped). The edge of the inner lobe extends down the side

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of the scale and curves up from below toward the outer rounded apex to form a grooved end (marginate).

Corona: Apex - apex Apex - center Widest Ret. - ret. Ret. - C Aw. - aw. Aw. - ret. Aw. - C

0.30 cm. 0.34 cm. 0.12 cm. 0.08 cm. 0.10 cm. 0.22 cm. 0.08 cm. 0.22 cm.

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Hoya benguetensis Schlechter 1906

Bottom view of the corona enlarged about 8X. The scales are deeply channeled and the sides are finely diagonally sulcate. Anther wings protrude as with Hoya bordenii. Central column is thickened and prominent.

Top view of the corona and corolla sinus area enlarged about 8X. Inner lobes are short dentate, dorsal is broad in the middle with a broadened keel from apex to apex, outer apex narrowing sub- cute. Inner lobe does not reach the center, outer lobe exceeds the corolla sinus. Anther wing apically thickened and rounded also protrudes. Another view of the corona enlarged about 8X. Note the blockiness of the scales and the steep sides even on the inner lobe. Apex – apex 0.40 cm. Apex – center 0.50 cm. Widest 0.22 cm. Aw. – aw. 0.30 cm. Aw. – ret. 0.12 cm. Aw. – center 0.28 cm. Top and sides sulcate. Scale 0.26 cm. deep. Inner apex slops inward about 0.02 cm. from the vertical. Scale side view enlarged about 16X, to show more detail. Note how the inner lobe slopes inwardly and how low the anther lays. The scale side bulges out near the center and all the surface is finely sulcate. The anther wing is very deeply curved (scythe-shaped) and thickened. Column material below. No bilobed projections on the lobe sides as are present in so many hoya species.

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Hoya benguetensis Flower from Marylyn Rosario, Manila Philippines via Nadhanielle Simonsson, Sweden to Fresno, CA. by Torill Nyhuus May 2003

Top vier of corona and inside corolla surface enlarged about 16X. Coronal love outer apex exceed the corolla sinuses slightly. The anther wings are thick sided, deep and have a blunt apex, center part slightly extended (apiculate)

Central view of the corona and inner corolla in background. Inner coronal lobes are dentate dorsal keeled as a result, dorsal of scale is slightly cupped and with a slight umbo and domed short keel, surface is horizontal. Inner lobe does not reach the center so anthers are exposed. The pollinia lay very close together with a small retinaculum. Anther wings are thick and distinctive.

Lower surface of the corona enlarged about 16X. scales are grooved sides rapping evenly and with diagonal sulcations. Sides form an open pentagonal area in the central portion, there is a short thickened central column with fine hair cells. Anther wings protrude.

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Another digital photo of the center of the corona enlarged about 16X. Dorsal longitudinally sulcate. Apex - apex Apex - center Widest Aw. - aw. Aw. - center Ret. - ret. Ret. - center ret. - aw.

0.45 cm. 0.50 cm. 0.20 cm. 0.24 cm. 0.18 cm. 0.13 cm. 0.12 cm. 0.18 cm.

Side view of a coronal scale enlarged about 16X. Inner dentate lobe slopes downward. Anther exceeds the inner lobe, Anther wing sides deeply scythe shaped. Dorsal surface cupped, with slight forward umbo, edges slightly raised, outer apex narrowed acute.

Stylar table enlarged about 32X. Anther wings still intact. Center raised and head mealy in appearance.

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Hoya benitotanii Kloppenburg 2010

View of the flower enlarged about 8X. The crown is very similar to that of Hoya gigantanganensis except that the inner lobes are not as long, leaving much more of the anthers exposed. The bilobes are of the same configuration with the flattened upper surfaces which are longitudinally sulcate and the outer lobe apex drops off sharply as in the other species. Inner lobe spatulate, anthers covering staminal crown, and exceeding inner lobes. Outer lobes rounded with pronounced bilobes flat on top and noticeably sulcate extending beyond outer lobe apices.

Upper (left) and lower (right) views of the corona enlarged about 8X. The inner lobes flare out toward the apex and do not exceed the anthers in the center. Below the lobes are channeled but only a short distance toward the center where there is a prominent thickened column 0.12 cm. inside diam. and out 0.13 cm. and 0.12 cm. tall.

Apex to apex Widest Aw. to ret. Ret. to ret. Aw. to aw. Inner lobe extension

0.25 mm. 0.12 cm. 0.05 cm. 0.09 cm. 0.11 cm. 0.12 cm.

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Hoya benstoneana Kloppenburg & Siar

Inside view of the flower enlarged as above. Coronal lobes reach the corolla sinuses, retinacula and anthers are visible, inner coronal lobes touch in center. Outer lobes are raised above the center.

Bottom view of the corona enlarged about 20X. Surfaces are glabrous, finely sulcate except for the central column. Lobes are channeled from apex to very near the thickened spongy central column. Top view of the corona. Inner lobes are spatulate, nearly touch in center. Outer lobes are raised and acute, Dorsal with fine linear sulcation, edges rounded. Apex – apex Widest Ret. – ret. Aw. – aw.

0.11 cm. 0.10 cm. 0.06 cm. 0.14 cm.

Lower surface of a coronal lobe showing the channel from apex inward to the central column area, the rounded edges, with diagonal sulcations. Enlarged about 32X.

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Side view of a coronal lobe and the short stylar crown below the inner apex. Outer apex raised, and acute, edges rounded, dorsal slightly sunken in center.

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Hoya benvergarai Kloppenburg & M. V. Siar 2008

Bottom view of the corona enlarged about 16X. lobes are channeled to near the elongated thin walled central column about 0.05 cm. tall, lobe surfaces sulcate. Apex – apex 0.40 cm. Apex – center 0.44 cm. Widest 0.24 cm. Ret. – ret. 0.12 cm. Ret. – center 0.12 cm. Aw. – aw. 0.24 cm. Aw. – center 0.22 cm. Anther wing (aw.) end is flat like in the species H. palawanica Kloppenburg and doubled (thick and end cupped). Extend beyond the sinus. Top view of the corona enlarged about 16X. Lobes lay horizontal, inner lobe short of center and sloping dentate with keeled top, dorsal concave slightly with central raised longitudinal ridge, outer apex somewhat blunt.. Pollinarium and anther wings below lobe surface. All glabrous. Anthers membranous with acute apices.

Coronal scale and anther wing enlarged about 32X to show the lobe sulcation and the details of the squared off anther wing apex. To the upper right is the central column.

Side view of a coronal scale, surfaces are glabrous and sulcate. Outer apex blunt and sloped down a little. Inner dentate lobe sloping downward toward the thin anthers. Anther wings deeply scythe shaped (buttery yellow color).

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Hoya betchei (Schlechter) Whistler (1908) 1978 Top view of the corona enlarged about 16X. Glabrous, center raised, inner lobes spatulate, outer lobes obtuse indented. Apex - apex Apex - center Widest Ret. - ret. Ret - center Anther wing - aw. Aw- - center

0.35 cm. 0.40 cm. 0.17 cm. 0.11 cm. 0.11 cm. 0.22 cm. 0.22 cm.

Top central view of the corona. The anther wings are narrow and protrude a little. Dorsal surface rounded with faint grooves. All surfaces glabrous. Retinacula plainly visible. Lower sides of lobes shelved and these reach the outer apex.

Bottom view of the corona enlarged about 16X. The lobes are channeled with sides diagonally sulcate. Center column is thickened. Scale outer apex obtuse. Anther wing ends narrowly blunt.

Side view of a scale enlarged about 32X. Inner lobe is sharply raised, Anthers exceed the inner apex. Outer apex is blunt obtuse and indented. Anther wings are not deeply scythe shaped. All surfaces are glabrous.

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Hoya bicknellii Kloppenburg 1999

Corona: scales upright, dull purple, inner angle spatulate, exceed the anthers but do not fold over the center, outer end rounded, central portion concave, bilobes flat and wide at central sides, apically extending with inner sides vertical, wedge shaped, apex pointed, and not curved in or up. The whole surface is finely sulcate. Outer apex reach the corolla sinus or slightly beyond. The lobes are thin as is the exposed portions of scale giving a skirt appearance from below. Column tall, 0.10 cm. or grater, opening 0.18 cm. Apex to apex 0.20 cm., apex to center 0.21 cm., center to lobe apex 0.27 cm., anther wing - anther wing 0.18 cm., anther wing apex - center 0.20, retinaculum - retinaculum 0.06 cm., retinaculum to anther wing apex 0.12 cm.

Note: The corona is sitting in a cup of the corolla. The corolla turns under at the ends. The bilobed apexes slightly exceed the sinus of the corolla. The crown is raised in the center The bilobed extensions are rounded on the outer surface and flat on the inner surface.

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Top View of Corona Approx. 65X.

Apex - apex Apex - center Ret. - ret Ret. - center Aw. - aw. Aw. - center

0.20 cm. 0.21 cm. 0.06 cm. 0.06 cm. 0.18 cm. 0.20 cm.

Bottom View of Corona Approx.65X.

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Hoya bicolensis Kloppenburg & Siar

Bottom view of the corona enlarged about 16X. Lobes are channeled sides sulcate and overlap near the middle, apex acute, central column well developed, 0.06 cm. tall.

Top view of the corona, outer lobes acute, inner lobes dentate and do not reach the center, surfaces glabrous, dorsal with center raised (keeled) edges raised in distinct pattern. Apex – apex Apex – center Ret. – ret. Ret. – center Aw. – center

0.24 cm 0.27 cm. 0.17 cm. 0.06 cm. 0.13 cm.

Top view of a flower, coronal lobes exceed the corolla sinuses.

Side view of a coronal scale. Outer apex emarginate and acute also raised a little. Inner lobe sharply curves up and is dentate, anther wings deeply scythe shaped. Sides of lobes a little concaved. Surfaces glabrous

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Hoya bicolor Kloppenburg 2003

Side view of the flower enlarged about 8X. The corona is white and the corolla pale with rosy tips, a beautiful flower! The corona is nearly horizontal slightly raised at both apices with the dorsal somewhat concave.

Top view of a flower enlarged about 8X. The inner coronal lobes are short and dentate and do not reach the center. Cupped dorsal surface has a raised center portion all the way to the outer apex that is acute and exceeds the corolla sinuses.

Bottom view of the corona enlarged about 8X. This surface is channeled well in from the sinuses toward a small raised column. Note the thick anther wing sides. Apex - apex Apex - center Widest Anther wing- aw. Retinaculum - ret. Aw.- center Ret. - center

0.30 cm. 0.34 cm. 0.15 cm. 0.20 cm. 0.08 cm. 0.18 cm. 0.06 cm.

Side view of a scale enlarged about 8X. The scale is actually somewhat short and deep. The anther wings are deeply scythe shaped. Anthers exceed the inner lobe.

View of the pentagonal stylar table enlarged about 8X. The center is raised into a narrow white spire on a small table.

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Hoya bilobata Schlechter 1906

Top view of a flower enlarged about 16X.The inner apex of the corona does not reach the center so the anthers are well exposed; this lobe is spatulate, relatively broad and has a keel in the center, just to the sides and below this the scale top in slightly concave. The outer apex is obtuse. Below on each side are wide tongue-like lobes, which extend beyond the apex.

Bottom view of the corona enlarged about 48X. The bilobes here form the channel. There are several species in the Section Acanthostemma. These lobes are finely longitudinally sulcate, the ends obtuse and in some clones fold over each other at the apices slightly. On the scale to the upper right the apex of the scale above is visible through the channel. The tissue inside from the lobes is warty or pre hirsute.

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Skewed view of the underside of the corona enlarged about 48X. In the center there is a relatively long column, you can see some of the bilobes wrap over each other at the ends, the diagonal sulcations can be seen especially on the lobes to the left.

Corona: Apex - apex Apex - center Widest Ret. - ret. Ret. - center Aw. - aw.

0.13 cm. 0.15cm. 0.05 cm. 0.06 cm. 0.05 cm. 0.10 cm.

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Hoya blashernaezii Kloppenburg 1999

Top view of the corona and inner corolla surface enlarged about 8X. Inner lobes are shortly dentate, much lower than the raised outer lobes. Dorsal surface is somewhat narrow and slightly keeled down the center; edges are a little sharp. Below a narrow shelf on each side starts beside the outer apex of the anther wing and extends to the coronal lobe apex. Anther wings are very straight and the sides are thick, ending in a protruding rounded apex. The inner surface of the corolla is finely pubescent. Outer coronal lobes exceed the coronal sinuses, inner lobes are short of the center. Bottom view of the corona enlarged about 8X. The outer lobes are raised upward at a steep angle so the lower channel is exposed to view. The edges forming the channel are concave from near the apex, a considerable distance inward. In the center there is a large short column, much thickened. The anther wings are protruding and with fleshy (fat) walls. Surfaces, which form the coronal channel are diagonally finely sulcate. Side view of the corona enlarged about 8X. Outer coronal lobes are raised, thick heavy anther wings and a relatively long column below. Apex - center 0.29 cm. Widest 0.12 cm.

Side view of a coronal scale enlarged about 16X to show more detail. Inner lobe just above the projecting acute anther apex (left). The outer lobe thick with rounded sides projecting upward, the apex marginate due to the narrow side lobes starting as little rounded protrusions at the base (right and curved under to form the sides of the channel and proceeding to the outer apex). Material in the center below is the column.

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Corona: on column 0.05 cm tall and base 0.13 cm. wide. The outer coronal lobes are very elevated tapering to an acute apex and keeled down the center above, below channeled and the inner lobes short and dentate, with the anthers exceeding; apex to base 0.32 cm., anther wing to anther wing 0.20 cm.; widest inward from the middle 0.14 cm. Center to outer apex 0.37 cm.

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Hoya bordenii Schlechter 1906

Bottom view of the corona. The lobes are channeled, there is a short central column. Anther wing apices are blunt, all surfaces are glabrous. sepal apex is acute.

Top view of the corona inside the corolla. The crown is horizontal, dorsal surface a little concave with a low umbo forward, inner lobes short and do not reach the center. Apex – apex Apex – center Widest Aw. – aw. Ret. – ret.

0.27 cm. 0.31 cm. 0.17 cm. 0.19 cm. 0.10 cm.

Side view of a coronal scale, surface is finely sulcate, glabrous. Anthers exceed the inner lobe apex, outer apex bent down slightly and blunt.

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Hoya brevialata Kleijn & Donkelaar 2001 Top view of a flower enlarged about 16X. The corolla is glabrous on the outside, pubescent inside except for the apical tip. Apex acute. sinus-sinus sinus-apex center-apex widest

0.28 cm. 0.35 cm. 0.50 cm. 0.31 cm.

Corolla not cut 1/2 way. Corona outer lobes reach corolla sinus, scales bilobed do not recurve over apex, inner lobes spatulate, do not quite reach the center. Lobes raised to the center. Anthers not extended.

Bottom view of the corona enlarged about 16X. Note the flattened outer apex of the bilobes, their sides roll under to form a relatively long channel almost reaching the column in the center. Apices of the bilobes are broadened and rounded. center-apex center to lobe apex Apex - apex widest anther wing -aw. retinacula to ret. center to ret.

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0.29 cm. including bi-lobe. 0.21 cm. 0.18 cm. 0.12 cm. 0.13 cm. 0.07 cm. 0.08 cm.

Side view of the corona enlarged about 16X showing two coronal lobes and the intervening anther wing area starting well up on the scale side but also the slit extends below to where the sides of the bilobes meet. The scale proper is cut off at the outer apex and here you can see the inner apex extending above.

Top view of the corona enlarged about 16X. The coronal scales are somewhat triangular in shape (top view), inner lobe is broad and relatively short and spatulate. The anthers are short and also the anther wings are short. Anther wings are unusual, in that they end in a broad outer bump adjacent to the sinus of the coronal scales; then extend below more narrowly. The outer lobes are broad, rounded on the outer (distal) sides straight edged on the inner sides (proximal).

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Hoya brittonii Kloppenburg 1992

Bottom view of the corona enlarged about 10X. Note the lobed annulus surrounding the central column, above this “skirt” the lower sides of the outer apices of the 5 coronal lobes are visible.

Top (inside) view of the flower enlarged about 8X. The corona is relatively small the lobes not reaching the corolla sinuses. The villous pubescence on this surface of the corolla is evident. In most of the flowers on this herbarium sheet were not open and I have noted this species on other sheets with the same trait.

Another view of the bottom of the corona enlarged about 8X, showing the very distinct and large column supporting the corona.

Top view of the corona enlarged about 8X, note the thick walled, very prominent anther appendages. The outer portions of the coronal scales are thin, inner lobes do not reach the center.

Corona: small, low dome shaped. Central 5 lobes with inner angles tapering to a short blunt apex, outer angles broadly rounded, translucent and raised as in Otostemma, also cupped on the upper surface, below on each side arise two additional tongue like

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extensions which are a partial annulus, instead of being a continuous annulus (skirt) they are divided below the outer apex of the anther wings, the skirt extends from under the outer apex of the coronal lobe and extend on either side of the central scale. In a dry specimen they diverge at 45 degree angles, instead of hanging down like an annulus or skirt. The outer surfaces of the prominent fleshy anther appendages are covered by the extensions of the lateral lobes, which in fact is a divided annulus. The surface curves under the anther wings then around and over the edge, covers about 1/2 or more of the wings upper surface. (It is similar to a 5 fid convoluted annulus with one portion on either side projecting laterally from under the coronal scale at a 45 degree angle). Apex to apex 0.11 cm.; Apex to center 0.11 cm.; Widest 0.06 cm. Ret.- ret. 0.05 cm. Ret. - center 0.04 cm. lower surface apex to collar 0.07 cm.; Anther wing outer apex to anther wing outer apex ca. 0.07 cm. Anther wing length 0.045-0.05 cm.

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Hoya buotii Kloppenburg 2002 Top view of the corona and inside surface of the corolla enlarged about 8X. The coronal lobes do not reach the sinus, are raised slightly in the center and the outer lobes also raised. Corolla surface is densely hirsute except under the corona. The anthers are creped in the center.

Side view of the removed corona, inner lobes and outer lobes raised, thick and fleshy. Inner lobes rounded and spatulate, darker in color. Outer apex turned over slightly, blunt, dorsal rounded and slightly keeled. Apes - apex Apex - center Widest Anther wing- aw. Retinaculum - ret. Anther wing - center

0.45 cm. 0.50 cm. 0.25 cm. 0.25 cm. 0.12 cm. 0.22 cm . Bottom view of the corona enlarged about 8X. This surface is channeled and the sides are sulcate, the channels extends only to the sinuses. The anther wings are doubled and project with an acute apex. The central column is thickened and short.

Lower center is the staminal pentagonal crown enlarged about 8X. The center is raised but simple in structure, small. The dorsal surfaces of the lobes show the central raised, rounded keeled area and the depth of the scales.

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Side view of an individual scale enlarged about 8X. Inner and outer apices are raised, so sway backed in the central region. Anther wings are not deeply configured. Anther is creped and rises above the scales inner apex.

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Hoya burtoniae Kloppenburg 1990

Corona enlarged about 8X. Inner lobes spatulate (beginning to dry and turn outward). Lower lobe ends abruptly between the two side lobes. Dorsal is slightly concave (raised edges) with a long ridge or umbo down the center. Bilobes are flat above and the vertical sides meet beyond the outer lobe apex.

Apex - apex Apex - end Apex - center Widest Ret. - ret. Ret. - center Aw. - aw. Aw. - center

0.16 cm. 0.20 cm. 0.20 cm. 0.07 cm. 0.07 cm. 0.07 cm. 0.12 cm. 0.15 cm. Bottom view of the corona enlarged at least 16X. The lobes are channeled down the middle with the sides sulcate. There is a central column and from here there are five fleshy protrusions toward the channel entrance (a similar structure is found in H. memoria Kloppenburg except there the fleshy lobes are bifid). The area between each lobe is rounded to the anther wings making a continuous pentagonal ridge.

Side view of a coronal scale enlarged about 16X. Left upper is the membranous anther with the yellow anther pocket showing. Above this is the spatulate inner lobe turning out on darting. Dorsal surface is at a 45° angle. The bilobes begin well up toward the inner lobe and a considerably distance beyond the abruptly ending of the outer coronal lobe Lower right). Anther wings are deeply scythe shaped (lower left center).

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Hoya cagayanensis Burton 1987 Data from PNH s.n. Elmer as cagayanensis.

Under side of a coronal lobe enlarged about 16X. Glabrous, finely sulcate, channeled nearly to the central column. there are fairly wide side lobes that reach the apex resulting in an emarginate end. Apex – apex Column

0.40 cm. 0.06 cm. long.

Top view of the corona enlarged about 16X. The inner lobes here were spatulate and met at the center. Dorsal widest 0.16 cm. and 0.25 wide below where the side lobes are flat on top and rather noticeable extending to the outer apex.

Flowered by Dr. Monina Siar

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Hoya campanulata Blume 1826

Photomicrograph enlarged approx. 16X. This is a large flower with big parts. Side view of Coronal scale enlarged approx. 16X. Note: The small inner lobe overtopping the small anther. Anther shield in lower center is relatively small. Outer lobe is large and rounded.

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Top view of the corona enlarged approx. 16 X. Dark areas are the retinaculum. The inner lobes although difficult to distinguished meet at the center with only a small portion of the anthers showing. The inner coronal lobe is spatulate as are most Section Acanthostemma species and here they are curved somewhat like a chickens upper beak.

Note: here and above that the outer coronal lobe is bilobed. On this photo the apex shows up as a red dot and the cleaved bilobed apices are beyond.

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Corona: glabrous, outer apex of scales indented. Scales are bilobed. Inner angle finely punctate. Apex to Apex Apex to center Widest Ret. to Ret. Ret. to center Anther wing to AW.

0.67 cm. 0.70 cm. 0.28 cm. 0.10 cm. vary in width. 0.19 cm. 0.40 cm.

Staminal head: short and finely capitate (Simple).

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Hoya camphorifolia Warburg 1904

Inside view of the flower enlarged about 8X. Corolla inside finely pubescent deeply lobed, lobes broad above the sinus. Corona very small with lobes not reaching the corolla sinuses. 0.10 cm. in diameter. Inner lobes narrowly spatulate or rounded, not reaching the center slightly raised but well below the raised outer lobes. Dorsal surface cupped in from outer apex edges rounded.

Bottom view of the corona enlarged about 16X. The lobes are short in this view and with blunt apices, shortly channeled below with edges finely sulcate. What you are seeing is actually the base of the corona and the lobes actually rise upward and so the channel is actually much longer. There is a large short thickened central column. Anther wings narrow and projecting a little.

Side view of the same corona enlarged about 16X. Here the rest of the upraised outer coronal lobe is visible with its channeled underside, apices tapering to a rounded point actually a little apiculate.

Top view of the corona enlarged about 16X. Inner lobes do not reach the center and are lower than the outer lobes which are obtuse, but actually shortly apiculate and cupped on the dorsal surface. Apex - apex Apex - center Widest Ret. ret. Ret - center Aw. - aw. Aw. - center

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0.15 cm. 0.18 cm. 0.10 cm. 0.05 cm. 0.05 cm. 0.10 cm. 0.10 cm.

Hoya cardiophylla Merrill 1920 Top view of the corolla and corolla enlarged about 8X. The coronal lobes reach the sinuses of the corolla, inner coronal lobes are short and do not reach the center, anther wings are doubled. Corona is horizontal. Corolla apices are acute. Apex – apex Apex – center Widest Anther wing – aw. Retinaculum – ret. Ret. – center

0.25 cm. 0.28 cm. 0.15 cm. 0.17 cm. 0.08 cm. 0.06 cm.

Bottom view of the corona enlarged about 16X. This surface is channeled and finely sulcate, center with a column.

Side view of a flower enlarged about 8X. Corolla lobes are reflexed, apices revolute. Corona lying flat with center slightly raised. Color pale yellow.

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Side view of a coronal scale enlarged about 16X. Scale is horizontal, inner lobe spatulate but short of the anther. Ventral surface slopes up to the outer apex. There is a slight keel down the dorsal surface, see top view of corona above.

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Hoya carmelae Kloppenburg, Siar & Ferreras 2010

Inside surface of the flower with corona. Corolla inner surface is glabrous. Coronal lobes exceed the corolla sinuses. Apex – apex Widest Ret.- ret. Ret. – center Aw. – aw. Aw. – center

0.24 cm 0.09 cm 0.06 cm 0.05 cm 0.11 cm 0.11 cm.

Bottom view of the corona enlarged about 40X. The coronal surface as well as the shape is unusual. Surfaces are sulcate-granulate, lobes appear to be channeled. Al surfaces are glabrous.

Corona top view of center, surface is granulatesulcate, inner lobes are drawn out long narrow spatulate, touch in the center, anthers visible between the lobes, the dorsal is horizontal with a concave area near outer apex. Enlarged as above.

Enlarged 23X to show the coronal lobe outer apex that is unusual in hoya species, Most visible on upper left lobe apex. The sides at the apex are turned in over each other, surfaces As mentioned above are also unusual.

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Side view of a coronal scale enlarged ca. 30X. Note the dorsal edges rolled and wider near the outer apex also the concave areas below this and how thin it is forward (left). The thickest depth is 0.18 cm. Inner lobe stretches over the anther and is spatulate, horizontal.

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Hoya carnosa Robert Brown 1802

Bottom view of the corona enlarged about 16X. The lobes are doubly channeled, one channel formed by the lobe and one by the side extensions, this surface is rolled under at the anther wing line between two adjacent scales. The center has a slightly thickened and short column.

Corona: Apex to apex Apex to center Widest (top) Anther wing to aw. Retinaculum to ret.

0.44 cm. 0.51 cm. 0.25 cm. 0.30 cm. 0.14 cm.

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Top view of the corona enlarged about 16X. The outer coronal apex just reaches the corolla sinus. The inner lobes are spatulate and do not reach the center, so the anthers are showing. Retinacula are plainly visible. Note the underlying side lobes, which below on the previous picture curve under to form an inner channel. The scale back is glossy domed or slightly rounded. The corolla below the crown is pubescent.

Side view of a coronal scale still attached to the central crown (Gynostegium). The scale slopes down from the center and the outer apex in narrowly rounded. Inner dentate lobe is inferior to the creped anthers. Note the lower side lobes arising from the

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under side of the scale, this also forms a long curving anther wing. Here the column is plainly visible in its typical round, concave sided, below the actual central core. The edges of the stylar table are visible here as white-yellow diamond shaped extensions over the edge of the table, the coronal scales would be attached between these areas. These diamond areas would be the stigmas on the top edge the Retinacula would be secreted.

Top view of the pentagonal table with all coronal scales removed, some free pollinaria here and there. Enlarged about 16X. The center is raised into an irregular dome, under each corner of the table is the receptive area of the stigma.

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Hoya caudata J. D. Hooker 1883

Inside view of the corona enlarged about 8X. The inner lobes are raised, do not reach the center and dentate. The dorsal is somewhat sway backed. Outer apex is obtuse. The whole structure is glabrous. The lower surface is channeled. Lobes do not reach the corolla sinuses. Apex - apex Apex - center Widest Ret. - ret. Ret - center Aw. - aw. Aw. - center

0.35 cm. 0.40 cm. 0.29 cm. 0.09 cm. 0.10 cm. 0.20 cm. 0.15 cm.

Side view of a individual coronal scale. Inner lobe is spatulate and raised. The anthers are unusual in being exceptionally long curving back over the center. Anther wings are not deeply curved. Back swayed and outer apex blunt and raised but much below the inner lobe.

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Hoya celata Kloppenburg & Siar

Under side of the corona enlarged about 16X. surfaces are glabrous, lobes are very finely sulcate and channeled down center, open edges rolled under. Area around the raised central column and under rolled edges of anther wings and lobe is evenly granulate, Ventral column about 0.20 cm. tall and with a 0.10 cm. opening (ovary cavity).

Under coronal apex is tightly revolute and also bifid enlarged about 16X. (The first species with these characteristics). Edges of the outer lobe here rounded, bilobes shelf-like.

Inside view of the corona enlarged about 16X. Inner lobes are raised and dentate, do not cover the extended translucent anthers. Outer lobe appears to be blunt obtuse but is curved edge of tightly revolute bilobed apex, note narrow shelf on upper edge of left, a bilobe extending toward the apex. Dorsal is raised in center. Apex – apex Apex – center Widest (dorsal) Ret. – ret. Ret. – center Aw. – aw. Aw. – center

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0.57 cm. 0.59 cm. 0.32 cm. 0.15 cm. 0.14 cm. 0.30 cm. 0.28 cm.

Side view of a coronal lobe enlarged about 32X. Note the long membranous anther (upper left). The raised inner dentate lobe with a raised keel along its dorsal surface, the plump rolled edges of the central part of the lobe and the tightly revolute bifid outer apex.

Greatly enlarged upper surface of the coronal lobe that shows the two side lobes as furrows beside the wider bulbous central portion (apical area below).

Corona enlarged about 16X with a lobe removed. Below center is the open column surrounded above by tissue of the coronal lobes. Top center the extended anthers, to the right lower the outer coronal lobe.

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Hoya chlorantha Rechinger 1908

View of inside of flower enlarged about 8X. Corona surface is shaggy pubescent and glabrous internally or very lightly puberulent. Coronal lobes raised in the center and spatulate, touching at center, Dorsal cupped with central slight raised center; outer apex rounded and does not reach the corolla sinus.

Corona top view enlarged about 8X. Apex - apex 0.45 cm. Widest 0.15 cm. Anther wing - aw. 0.20 cm. Aw. - center 0.20 cm. Retinaculum - ret. 0.10 cm. Ret. - center 0.10 cm. Anther wings thick and protrude a little.

Bottom view of the corona enlarged about 8X. Surface is channeled all the way to the short central thickened column.

Side view of a coronal scale enlarged about 16X. Surfaces are sulcate, inner apex raised but anthers exposed in the center, dorsal surface is concave. The anther wings thick, not too deeply scythe shaped, lower side lobes extends to the apex.

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Hoya chlorantha var. tutuilensis Christophersen 1935

Top view of the flower with lobe and sinus showing, The coronal lobes do not come near the corolla sinuses.

Top view of the corona enlarged about 8X. The surfaces are glabrous, waxy. Inner lobes are spatulate and raised, dorsal is slightly sway backed, outer lobe is emarginate. Dorsal is slightly domed, sloping downward a little near the apex

Bottom view of the corona enlarged about 8X. The sides forming the central channel overlap near the sinuses. There is a central thickened column 0.05 cm. tall.

Side view of a coronal scale enlarged about 16X. Note the inner lobe is exceeded by the anther, the dorsal is sway backed and a little cupped, the outer apex bends over slightly. Anther wings are fairly deeply scythe shaped. Apex - apex Apex - center Widest on top Ret. - ret. Ret. - center Aw. - aw. Aw. - center

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0.34 cm. 0.38 cm. 0.17 cm. 0.09 cm. 0.08 cm. 0.20 cm. 0.18 cm.

Hoya chunii P. T. Li 1984

Top view of the crown and corolla, enlarged about 16X. Note: the scales reach the corolla sinus. The inner lobes are dentate and very short and stubby, outer apex slightly rounded. The anthers are well exposed in the center. The corolla is densely and finely pubescent. Dr. Schlechter commented on how different this pubescence was.

Bottom view of the corona enlarged about 16X. The lobes are channeled and at the apex separated, meeting and terminating the channel inwardly. This surface is finely sulcate. In the center there is a short column.

77

Side view of a corona scale again magnified about 16X. The short dentate inner scale is clearly seen, and in front of it to the left is the anther and one pollinarium identified here as a dark reddish spot under the inner scale apex. The whole scale and crown lies horizontally. Corona: fully channeled below, horizontal, short inner lobe, tapered outer lobe. Apex to apex Center to apex Widest Retinaculum to ret. Ret. - center Aw. - aw. Aw. - center depth (thickness)

0.22 cm. 0.25 cm. 0.14 cm. 0.08 cm. 0.06 cm. 0.14 cm. 0.12 cm. 0.09 cm.

78

Hoya cinnamomifolia Hooker 1848

Bottom view of a coronal scale enlarged approx.16X. Note the fine sulcation, which covers all exposed surfaces of the scale. On this side the scale is tightly channeled. Anther wings extends out from above slightly.

Top view of the corona enlarged about 16X. Note: the sulcation also on this surface, the keeled groove down the top center, the short dentate inner coronal lobes not reaching the center. The anthers are here well exposed in the center, the pollinarium and the shortened anther groove are visible. 79

Side view of a single coronal scale enlarged about 16X. Note: the very short dentate inner lobe and again the fine sulcations on the surface.

Top view of the corona with all scales removed but one leaving the pentagonal stylar table exposed. Part enlarged about 16X. Note: the conformation of the top of the coronal scale and how the short inner lobe looks like it was formed by being pinched between ones fingers, the typical dentate structure. Hoyas can be divided into 3 groups as far as I know now, either with this dentate inner lobe, a flat spatulate inner lobe as in most Section Acanthostemma hoyas or round (sort of a modified dentate form, few of these). The center here was referred to as the stigma by most authors in the older literature. This structure varies somewhat from species to species, here it is a cone topped with a loose assemblage of cells. A line runs to each edge of the pentagon where the retinaculum of the pollinarium would rest.

Apex - apex Apex - center Widest Ret. - ret. Ret. - center Aw. - aw. Aw. - center

0.40 cm. 0.42 cm. 0.27 cm. 0.08 cm. 0.10 cm. 0.20 cm. 0.25 cm.

80

Hoya citrina Ridley 1922

Side view of the flower, showing mainly the crown enlarged about 16X.

81

Top view of corona and part of corolla below enlarged about 16X. Note the lobes of the corona exceed the corolla sinus. The inner lobes are relatively short and dentate not reaching the center so the anthers are well exposed. The retinacula are visible as are the anther grooves. The corolla inner surface is finely pubescent and outside glabrous.

Bottom view of the corona enlarged about 16X. There is a covered channel and the turned under surface is beautifully sulcate. The anther wings protrude beyond the sinus, the outer lobe is acute. 82

View of the stylar pentagonal crown with all coronal scales remover except one. The stylar crown is a simple peak, the 5 corners where the stigmas are visible as rose colored areas on an otherwise yellow surface. Not the coronal scale has a ridge in the center toward the outer apex. Several pollinaria are visible as well as anthers pealed back.

Corona: Apex - apex Apex - center Widest Ret. -ret. Ret. - center Aw. - aw. Aw. - center

0.33 cm. 0.39 cm. 0.18 cm. 0.09 cm. 0.08 cm. 0.22 cm. 0.21 cm.

83

Hoya clemensiorum Green 2001 Top view of the corona with corolla below enlarged about 8X. The inner lobes are short small and dentate. The outer lobe is emarginate, dorsal is narrowly ovate, horizontal, with as slight ridge down the center. The outer lobes exceed the sinuses. There are narrow side lobes beginning at the outer end of the anther wings proceeding along the base of the scale outward. Skewed side view of the corona enlarged about 8X. Note how flat the corona is with a slight cup in the dorsal surface and a slight keel down the center. Most notable in this species is the very thick (doubled) anther wings, they occupy the entire space between the coronal scales. Apex to apex Apex to center Widest Anther wing to aw. Ret. to ret. Aw. to ret. Ret. to center

0.34 cm. 0.36 cm. 0.11 cm. 0.19 cm. 0.08 cm. 0.09 cm. 0.05 cm.

Side view of a coronal scale enlarged about 8X. The dorsal is perfectly horizontal. Outer lobe somewhat blunt, Inner lobe extended and dentate. Here the anther has folded downward, it normally just barely exceeds the inner coronal lobe.

Bottom view of the corona enlarged about 8X. The bottom is deeply channeled just in from the anther wings leaving a pentagonal like blank area in the central section, the surfaces are finely sulcate, the column is fairly large but short. Here again the unusually thick anther wings are visible occupying all the space between the coronal lobes.

84

Hoya cominsii Hemsley 1890

Top view enlarged about 16 X of the corolla and corona of IML 457. The outer coronal lobes just reach the corolla sinus. The fine pubescence on the inner corolla surface is visible. Note the short inner coronal lobes, which do not extend to the flower center so the anthers are exposed. The corolla apex is acute here reflexed and glabrous. This species has vary narrow side lobes on the coronal scales so fits into my Section Angusticarinatae Kloppenburg.

Side view of a coronal scale enlarged approx. 16X. The scale is perfectly flat on top with a very short stubby inner lobe. This is a scale from a flower of IML 457. Note the slight differences in this and the one form DAV 819.

85

Top view of the corona of IML 457, enlarged approximately 16X. The scales here are a little longer and slightly mare narrow than in DAV 819. The top of the scale is somewhat concave in the center (visible on the upper right hand scale). The side lobes are discernable and they always form an indent in the outer apex in this section (marginate). Outer apex acute; inner dentate and really short. Corona: Apex - apex Apex - center Widest Ret. - ret. Ret. - center Aw. - aw. Aw. - center

0.36 cm. 0.40 cm. 0.21 cm. 0.09 cm. 0.09 cm. 0.20 cm. 0.19 cm.

86

Bottom view of corolla of IML 457 enlarged about 16X, note the pentagonal structure formed by the inner revolute under sides of the coronal scales, I have not noticed this so defined on other species. The channel sides are finely sulcate.

Side view of scale of DAV 819 enlarged about 16 X. You can see the fact that the top is flat and also concave, also that the inner lobe is dentate and well short of the anther in the center, here projecting upward at the left side. The outer apex here is a little more narrow and acute.

87

Hoya corazoniae Kloppenburg, Siar & Ferreras 2010

Corolla: Inside surface enlarged as above. This surface is scattered pubescent. Corona is bilobed with the lobes long and reach the corolla sinuses, inner lobes cover the center, are raised and spatulate, outer lobe is short ending abruptly and is sub-obtuse, dorsal is concave, edges sharp, thin.

Corona: bottom (ventral) view enlarged ca. 15X. Lobes are channeled from apex of the bilobes inward to even with the anther wings that have rounded under edges, center is a thickened column, all surfaces are glabrous.

Corona dorsal surface enlarged ca. 18X, bi-lobes are greatly extended rather thin in texture with linear surface sulcations, the normally meet at the apices. Anther wings protrude and have thickened rounded edges. Apex – apex Apex – end Widest Ret. – ret. Ret. – center Aw. – aw. Aw. – center

88

0.15 cm 0.24 cm 0.09 cm 0.04 cm 0.04 cm 0.15 cm 0.13 cm

Hoya coriaceae Blume 1826

Bottom view of corona about 16 X. Observe here the prominent thickened column with a few hirsute hairs at its base, the channel formed by the curled edges of the corona, and the outer end of the anther groove. Slightly less visible is the fine sulcation on this side.

Corona: Anthers exceed scale inner toothed apex, outer apex rounded, widest at center 0.25 cm., below 0.30 cm., anther wings deeply sunken, extended. Apex - apex 0. 61 cm. Apex- center 0.63 cm. diameter 1.26 cm. Widest 0.25 cm. Retinaculum - ret. 0.18 cm. Anther wing - aw. 0.30 cm. Aw. - Rt. 0.10 cm. There are hairs on collar ringing base.

89

Top view of the corona about 16 X. Note that the inner lobes are dentate and that the anthers are crepe-like exceeding the inner coronal lobes and extending almost to the retinaculum. The outer end of the lobe curves downward and has rudimentary bilobes along the thickened sides, the inner lobes are raised toward the center.

Side view of an individual coronal scale about 16X. Here we can see how the outer apex of the scale turns under and how much depth there is to the scale. The anthers clearly extend beyond the inner apex. A pollinia is still present, the side of the anther groove extends way down the scale side.

90

Hoya crassicaulis 1995 From Type sheet #14440 (B) Mt. Bulusan, Philippines. 5 flowers heavy stem, 0.5 cm. in diameter, internodes 1 cm + long. Leaf 13 + cm. x 5-6.5 cm widest, glabrous, base obtuse apex apiculate acute, nerves reticulate interconnected. Top view of flower enlarged about 16X. Corolla inside pubescent. Corona: Apex - apex Apex - center Widest Ret. - ret. Aw. - aw.

0.30 cm. 0.36 cm. 0.15 cm. 0.10 cm. 0.16 cm.

Color 0.02 cm in diameter 0.09 tall

Bottom view of the corolla. The coronal lobe apices exceed the corolla sinuses. Outside granulose and glabrous. Corolla is deeply cut. Central collar is thickened. Sinus - sinus Sinus - apex Sinus - center Apex - center Widest

0.25 cm. 0.38 cm. 0.20 cm. 0.50 cm. 0.34 cm.

Photomicrographs from #46116 (UC) Edano from Capaz, Panay Province, Pasol River, Philippines 2 Oct. 1925. Top view of the flower as above the coronal lobes exceed the corolla sinuses which are deeply cut. Sinus - apex 0.35 cm. Sinus - sinus 0.17 cm. Apex - center 0.50 cm. Widest 0.30 cm.

91

Photomicrographs from #900355 via Dexter Heuschkel Philippines Fresno, California bloom. 8/4/91 3 clusters 1st blooming 34 flowers with center forming new buds, flowers creamy yellow with bronze reflexed lobes, corona white and horizontal dorsal, outer apex turns up slightly.

Top view of a flower enlarged about 16X. Coronal lobes are upcurved at the outer apex. Inner lobes narrow dentate and do not quite reach the center, dorsal somewhat concave and horizontal. Inside corolla finely puberulent. Apex - apex Apex - center Widest

0.31 cm. 0.34 cm. 0.16 cm.

Bottom view of the corona. The anther wings are thickened and very prominent, protruding. Scales are tightly grooved on the underside, nearly to the central column. Collar 0.05 cm. tall, thin walled.

92

Hoya cumingiana Decaisne 1844 Under side of the corona enlarged about 8X. Note the thickened and relatively large column. This side is channeled with the surfaces finely sulcate. The narrow side lobes (Subsection Angusticarinata Kloppenburg) are visible extending to the outer apex. Column 0.17 cm. in diameter 0.07 cm. tall. Top view of the corona enlarged about 8X. Inner lobes are spatulate, rise in the center do not reach the center where the paper like anthers are exposed. Apex – apex 0.38 cm. Apex – center 0.44 cm. Ret. – ret 0.13 cm. Aw. – aw. 0.22 cm. Widest 0.14 cm. The anther wings are narrow and do not protrude beyond the corona cleft.

Top view of the outer coronal Apex enlarged about 8X.The outer lobe does not reach the coronal sinus. The apex is emarginate from the meeting there of the narrow side lobes. Note the coronal inner surface appears glabrous but is finely pubescent (puberulous).

Side view of a coronal scale and the very unusual stylar crown of this species enlarged about 10X. The center is ornately capitate. I’ll bet you could identify this species by this trait alone.

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Coronal scale side view enlarged about 8X. Inner lobe is spatulate, exceeded by the papery anther. Center much higher than the outer apex.

94

Hoya curtisii King & Gamble 1903 Side view of the flower enlarged about 8X. The corona sits way up on a long column with a flared skirt at its base. The corolla is reflexed, as is the calyx. Corona Apex – apex Apex - center Widest Ret. – ret. Ret. – center Aw. – aw. Aw. - center

0.23 cm. 0.28 cm. 0.17 cm. 0.14 cm. 0.13 cm. 0.18 cm. 0.18 cm.

I have enlarged this lower photo of the corona 16X to show the detail more clearly. The two lobes are not like the bilobes found in the Section Acanthostemma species but start below the coronal lobes, at their base and are broad flat structures that overlap on another in the center and extend out to sort of a bifid apex well down from the obtuse outer apex. I feel here again we have some modifications of what we can clearly distinguish as channeled species and bilobed species. I would say they are somewhat like the modifications found in Hoya kloppenburgii Green and Hoya gildingii Kloppenburg.

95

Again enlarged about 16X to show more detail. The inner lobes are almost not existent but are dentate, dorsal is horizontal cupped centrally with sharp raised edges, outer apex obtuse. Plate like bilobed projections arise below the lobes and extend outward and in sort of rounded edges below the outer apex. Not shown in Rintz’s drawing. (see next picture).

End view of the corona enlarged about 12X. Note the center coronal scale and how the bilobes are rounded and turn upward from below and meet in center below the outer coronal lobe. This is not shown in Rintz’s drawing.

96

Hoya cystiantha Schlechter 1913

Top view of the corona enlarged about 16X. This is a large corona, the lobes are narrow and long, bifid at the outer apex (marginate). The upper surface is striate the inner lobe appears to be dentate, nearly all bilobed species have spatulate inner lobes. These inner lobes do not reach the center so the anthers are well exposed. The crown has considerable depth in the central portion. Corona: inner lobe is not free of the anther even at the apex. Column short 0.05 cm. tall, lower side of lobe finely sulcate and channeled down center. Stylar table is shortly apiculate, cleavage of stigma visible. Center to apex Apex to apex Width (top) Anther wing-aw Aw to center Retinaculum-ret Ret to center

0.54 cm. not recorded 0.15 cm. 0.25 cm. 0.29 cm. 0.10 cm. 0.10 cm.

97

Bottom view of the corona enlarged about 16X. Note the long narrow lobes with rounded (obtuse) ends, the lobes are channeled and finely sulcate; the areas around the column are covered with long stellate hairs, most pointing outward from the center.

Side view of the coronal scale enlarged about 16X. The inner lobe rises to the center but is overtopped by the anther. The lobe narrows as it approaches the outer apex.

98

Hoya darwinii Loher 1910

View of the lower surface of the corona enlarged about 8X. Scales are channeled to even with the sinuses. In the center is a thickened column surrounded with velvety twisted hairs, The anther wings are thick and protrude. Apex – center Widest

0.80 cm. 0.41 cm.

Top view of the corona enlarged about 8X. All surfaces glabrous. Inner lobes narrow long and dentate; touching in the center. Outwardly the lobe broadens with the outer apex obtuse, narrow side lobes are present. Anther wings with thick sides and project beyond the sinus. Outer lobes are greatly raised above the center so the channeled lower surface is visible in the natural state.

99

Hoya davidcummingii Kloppenburg 1995 Corona: fairly upright, inner apex of lobes spatulate and upon drying turn outward at a 90° angle to the central axis, anther apices triangular, membranaceous extending will above the stylar head, prominent and visible, outer apex broadly obtuse; scale saddle shaped in cross section, broad on top with a central ridge, yellow centrally rose; two long broad bilobes from side and under scale incurving at apical ends especially near maturity and on drying. Apes-apex 0.18 cm; apex-end 0.26 cm.; center to apex 0.22 cm.; widest part of scale top 0.12 cm.; anther wing apex - anther wing apex 0.17 cm; retinaculum (inner apex) - retinaculum 0.07 cm.

Photomicrograph of flower side view approx. 16X.

100

Hoya densifolia Turczaninow 1848

Bottom view of the corona enlarged about 8X. The underside is channeled well in toward the column, surface sulcate. The column is relatively long and thickened. Apex - apex Apex - center Widest Ret. - ret. Ret. - center Aw. - aw. Aw. - center

0.30 cm. 0.35 cm. 0.15 cm. 0.12 cm. 0.14 cm. 0.21 cm. 0.30 cm.

Top view of the corona enlarged about 8X. The inner lobes are spatulate, do not quite reach the center and are raised. There are narrow side lobes so it fits in the subsection Angusticarinata Kloppenburg. The outer apex is emarginate.

Skewed view of the corona and reflexed corolla enlarged about 8X. Note the very fine puberlance on the upper corolla surface especially near the corona. This view shows the narrow side lobes extending to the coronal outer apex with a 3 way meeting of apices to form an emarginate apex.

Side view of the corona perched above the reflexed corolla enlarged about 8X. The inner lobes are very upright and the lower lobes jut out almost perpendicular, the narrow side lobes are plainly visible here. There is a skirt like flare between the lobes at their base.

101

Side view of a coronal scale enlarged about 16X. Inner lobe points almost vertically whereas the outer lobes lays nearly horizontal, narrow side lobes extend from the anther wing area to the outer apex. Anthers are below the inner lobe but not covered by it.

102

Hoya deykei Green 1990

Top View of Corona approx. 16X. Note: Outer lobes rounded. Inner lobes dentate and do not reach the center. Scales with reduced side lobes placing it in the Subsection Angusticarinata Kloppenburg.

Bottom View of Corona approx. 16X

103

Note: Finely sulcate turned under coronal edges forming a hollow channel below, prominent anther wings, central column; outer lobes narrowing but rounded.

Side view of a scale enlarged about 16X.

Side View of Flower approx. 16X. Note: The flat corona, channeled undersides of scales, reflexed corolla with lobes slightly recurved ant acute, glabrous on outside, papilose on the inside and granulate, coronal scales just reach sinus or slightly exceed it. Pedicel terete glabrous with numerous lenticels. (a composite photomicrograph).

104

Corona:

Apex - apex Apex - center Widest Anther wing - aw. Ret. - ret. Ret. - aw. Ret. - center Center - aw

0.25 cm. 0.30 cm. 0.15 cm. 0.18 cm. 0.09 cm. 0.08 cm. 0.07 cm. 0.16 cm.

lobes sulcate (finely lined), channeled below, column 0.03 cm tall x 0.10 across, top nearly horizontal, very slightly concave toward center, slight central keep and small umbo near inner lobe.

105

Hoya diptera Seemann 1861

Bottom view of the corona enlarged about 8X. The narrow bilobes roll under to form a channel and even overlap each other in the inner portions. The lobes extend to the apex, which is curved under slightly. The lobe surfaces are sulcate. In the center is a well formed, thickened column.

Top view of the corona enlarged about 8X. Scales have a rather narrow top with narrow bilobes extending don the lower sides of the scales and meeting just before reaching the outer apex, which is narrowly rounded. Inner lobes are short, narrowly rounded and do not reach the center. The anthers are very broad, close over the domed stylar center.

Anther wings (2) considerably enlarged. The bottom one with the apex to the right. The anther envelopes, two in each anther are a deep yellow and thickened whereas the remainder of the anther is very membranous. The anther base is very broad. I usually do not show the anthers but they are significant and differ among the different hoya species.

106

Stylar pentagonal crown enlarged about 16X. The pentagonal area shows up as rich yellow the raised center is domed with a slight apiculate center. On the two top corners you can still see the retinacula attached in their normal positions. To the far upper left is an anther folded back, and below some of the column material.

Side view of the stylar crown enlarged about 8X. Note the striated sides of the center and the small apiculate apex.

Side view of a coronal scale enlarged about 8X. Outer lobe sloping to a narrow rounded apex inner lobe shot spatulate inner lobe. Scale is rather deep and not with prominent anther wings.

Corona: Apex - apex Apex - center Widest Ret. - ret. Ret. - center Aw. - aw. Aw. - center

0.30 cm. 0.34 cm. 0.16 cm. 0.07 cm. 0.07 cm. 0.16 cm. 0.14 cm.

107

Hoya dischorensis Schlechter 1913

Top view of the flower enlarged about 8X. Outer coronal apex does not nearly reach the corolla sinus. Note here the pubescence all the way in and villous edging, corolla lobes wide above the sinus.

Bottom view of the corona enlarged about 8X, Lobes channeled, and rolled sides sulcate almost laterally. Central column relatively long, thickened. Anther wings project, are thin. Lobe apex turns under.

Top view of the corona enlarged about 8X. Inner lobes short, dentate and do not reach the center where the anthers meet. Dorsal surface cupped forward domed outward. Anther wings narrow and protruding. Apex – apex Apex – center Widest Aw. – aw. Aw. – ret. Ret. – ret. Ret- center

108

0.044 cm. 0.47 cm. 0.23 cm. 0.26 cm. 0.12 cm. 0.12 cm. 0.12 cm.

Side view of the corona on the corolla enlarged about 8X. Note the outer apex is nippled and turned under, otherwise obtuse. Inner lobes slightly higher than the outer apex and do not quite reach the center.

Side view of the coronal scale enlarged about 8X. The outer apex sloped downward and turns under. Inner lobe raised but dies not exceed the anther. Scale 0.24 cm. deep. (Vertical depth).

Top view of the stylar pentagonal crown enlarged about 8X. One scale removed to show the apex of the stylar crown that is exposed to the left adjacent to the 3 left scales. Its sides are keeled and the apes 5 parted.

109

Hoya diversifolia Blume 1826

Top view of the corona. Bogor Botanical Garden collected in 1981. Flowers from Fresno, California blooming

Two more photos of the corona top view. Apex - apex Apex - center Widest Ret. - ret. Ret. - center Aw. - aw. Aw. - center

0.31 cm. 0.35 cm. 0.19 cm. 0.11 cm. 0.10 cm. 0.22 cm. 0.19 cm.

Top view of the corona. In the cline of this species the outer corona lobe apex vary. Some are more obtuse than others. In addition the central dorsal umbos are of differing shapes.

110

Side view of the coronal scale.

Bottom view of a coronal scale. Variations in the bottom channels are in the extent of the channel and the way in which the sides of the scale extend toward the outer apex. This difference determines the extent of the channel and thus the amount of the outer scale apex left free of the channel. The inner lobes are channeled below, a detail I did not observe until the photographs of the Kim Yap material was examined in 2003. (see below)

Below material sent from Singapore by Kim F. Yap 2003; collected in Malang, East Java collected by Kim F. Yap from Raintree February 2002

Top views of the corona and inner corolla enlarged about 16X. Corolla: Outside finely granulose crystalline with the edges rolled under sinuses and apex also. Inside pubescent, longer and more stellate under the coronal lobes and extending toward the sinuses.

111

Sinus - center Sinus - apex Sinus - sinus Apex - center Widest

0.45 cm. 0.54 cm. 0.53 cm. 0.62 cm. 0.55 cm.

Corona : dorsal surface concave with an umbo at base of inner lobe, surface finely sulcate, outer apex rounded, shortly apiculate, inner lobe tapering rounded not touching in center but overtopping the anther apices.

Corona lower surface view. channeled shortly in the central region of the scale with the sides diagonally sulcate. Apical area not channeled by the side lobe curved extensions. Apex - apex Apex - center Widest Ret. - ret. Ret. - center Aw. - aw. Aw.- center Center - sinus

0.30 cm. 0.32 cm. 0.18 cm. 0.10 cm. 0.10 cm. 0.22 cm. 0.20 cm. 0.45 cm.

The corona has basal side lobes from the anther wings 3/4 way out toward the apex . The collar of the corolla is thin ca. 0.05 cm. tall. Anther wings are rounded at the outer apex, narrow and slightly protruding beyond the sinus.

Bottom view of a coronal lobe showing the unusual channeling of the underside if the inner lobe. Apical areas of inner and outer lobe on the under side not channeled. Sides of scale broadly formed.

112

Side view of the coronal scale showing the thickness of the lobe and the inner lobe with the anther below. Anther wings are not deeply scythe shaped.

Another view of the lower side of the coronal lobes showing the channeled inner and main portion of the scale along with the portion of the outer lobe where the side extensions do not extend to form the channel. The mealy looking lighter colored material is the portion of the staminal column to which the coronal scale is fused.

Stylar crown with the raised mealy central crown greatly enlarged. All but one coronal scale has been removed.

113

Hoya diversifolia subspecies el-nidicus Kloppenburg 1991 Top (inside) view of the corona and corolla enlarged about 8X. The coronal scales are no where near to the corolla sinuses. Inner lobes are also short of the center so the rather thick anthers are exposed.

Bottom view of the corona enlarged about 16X. Scales are channeled and surface is sulcate, Here a portion of the corolla collar has adhered to the column hiding the center and the column edges.

Top view of the corona enlarged about 16X. Outer lobes are not rounded as in the Species H. diversifolia Blume rather s little pointed. Dorsal surface is cupped a little with an umbo in the center. Inner lobes are spatulate. Apex –apex Apex – center Anther wing – aw. Retinacula –ret. Ret. – center Aw. – center widest (scale top)

114

0.25 cm. 0.30 cm. 0.20 cm. 0.11 cm. 0.10 cm. 0.19 cm. 0.17 cm.

View of the stylar crown enlarged about 8X. The center is raised as usual with little modification. I would classify this as a simple type.

Top and side view of individual coronal scales enlarged about 16X. Anther visible under the inner lobe above, umbo in concave dorsal surface below.

115

Hoya dolichosparte Schlechter 1916 The following is photo-micrographic material from a cutting sent me by Ted Green, Kaaawa, Hawaii May 2004 with flower cluster. Dry but soaked in Kew solution, measured and studied with a binocular scope and an Olympus digital scope.

Top view of the flower, and corona enlarged about 16X. Scales are nearly horizontal. Inner lobe is dentate nearly reaching the center. Dorsal surface slightly cupped with an umbo centrally and slightly keeled in the center. Outer lobe is acute.

Top view of the corona enlarged about 16X. The anther wings apices are acute relatively narrow and glabrous. Apex - ape Apex - center Widest Ret. - ret. Ret. - center Aw. - aw. Aw. - center

0.40 cm. 0.42 cm 0.20 cm. 0.10 cm. 0.10 cm. 0.20 cm. 0.19 cm.

Bottom view of the corona enlarged about 16X. The lobes are fully and tightly channeled all the way to the central column. Side walls are finely sulcate. Surfaces are all glabrous.

116

Side view of a coronal scale greatly enlarged. Scale has a long slender outer lobe. Inner lobe is dentate and relatively short, exceeded by the anther (pollinarium remains adhered). Anther wings are deeply scythe shaped. Scale is relatively thick, dorsal is cupped slightly and nearly horizontal.

As above but slightly tilted showing the top surface of the scale with the forward umbo and low broad keel down the center.

117

Hoya edanoi C. M. Burton 1990 The following are photomicrographs from Sheet #44121 (UC) This was collected by Ramos & Edano 1 Aug. 1924 (flower red, small) on Tawitawi, Sulu Province, Philippines. Photographed 8/11/89.

Top view of the flower enlarged about 8X. Outer coronal lobes are rounded with wide bilobed extensions that go well beyond the outer apex; and their surfaces are sulcate. Bilobes reach the corolla sinuses. Corolla upper surface is pubescent, 1.14 cm diameter flattened. Apex – apex Apex to outer bilobed apex

0.22 cm. 0.26 cm.

Dorsal surface of coronal scales keeled a short way out from the inner lobe apex. Bottom is channeled. Outer lobe apex obtuse, inner is long extended and spatulate.

Another view of the flower enlarged about 8X. Flower diameter natural shape 0.60 cm. diameter flattened 1.14 cm. Inner lobe is spatulate rising in the center and above the anthers but not covering them. Outer lobe rounded, bilobes extending beyond and curving to meat at their apices. Outer apex just shy of the corolla sinuses.

Side view of a coronal scale enlarged about 16X. Inner lobe is raised well about the outer lobe. Bilobed extensions extend well beyond outer lobe apex. Dorsal surface is slightly cupped with a keel down the center and edges slightly raised .

118

Hoya eitapensis Schlechter 1909

Side view of a coronal scale enlarged about 16X. The inner coronal lobe is spatulate and overtops the anthers, the center is raised and the scale slopes outward slightly. There are narrow side (bilobes) which meet at the apex.

This species is a Section Acanthostemma (Blume) Kloppenburg; Subsection Angusticarinata Kloppenburg species.

Bottom view of the corona enlarged about 16X. The scales are channeled below and the surface is finely sulcate. The narrow side lobes are visible and extend to the outer apex, which is then emarginate. Corona: Raised slightly toward the center, Inner lobe spatulate meeting at the center, scales are narrowly bilobed and lobes meet at the outer apex to form an emarginate apex. Scales 0.34 cm. long at the widest near the inner lobe 0.11 cm.; diameter 0.70 cm., scale depth 0.22 cm. Channeled below and surfaces are finely sulcate. Retinaculum retinaculum 0.08 cm. Ret. - center 0.07 cm. Anther wing - aw. 0.18 cm. Aw. - center 0.15 cm.

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Top view of the corona enlarged about 16X. The inner spatulate apices meet in the center. The scales are long and taper from the ends of the inner lobe toward the emarginate apex. The narrow side lobes form along the sides near the Retinaculum and extend all the way to the apex. The dorsal surfaces of the scales are slightly convex.

The stylar table with a mealy raised center here enlarged about 16X. Two pollinaria are still attached to the edge of the table. (here all the coronal scales have been removed.

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Hoya elliptica Hooker f. 1883

A skewed view of the lower side of the corona enlarged about 16X.There is a rather prominent column, which is fairly thin and round. The outer scale lobes are channeled below to deeply inside the sinus area and the remainder of the space to the column is covered with long stellate hairs pointing outward form the center. These outer scales are pointed upward. The anther groove here has dried a little and split open on the upper right center.

Top vier of the stylar crown with the scales and the anthers pulled back or removed enlarged about 16X. This style apex is the most elaborately structured of all the hoyas I have examined. It is readily apparent why so many taxonomists of the past took this structure to be a central stigma.

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This is a view of the stylar crown enlarged about 48X. Note its elaborate structure. There are two pollinaria showing (actually only the pollinia) which have become dislodged in removing the coronal scales. Why such a elaborate structure I do not know. (its use or function or evolutionary significance). Corona: Apex - apex Apex - center Widest Ret. - ret. Ret. - center Aw. - aw. Aw. - center

0.42 cm. 0.42 cm sharp keel 0.18 cm. 0.18 cm. 0.23 cm. 0.20 cm.

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Side view of a coronal scale enlarged about 16X. The outer lobe is very upright channeled on the outside (normally the lower side of the scale) and keeled above. The inner lobe is spatulate and the keel extends to its apex. The anther is attached below. Anther appendages below have considerable depth, indented in the end but otherwise relatively thin. One pollinia remains attached with here a long retinaculum.

Photomicrographs from flowers sent to me from Thailand by Chanin Thorut in 1992. Photos June 20, 1992.

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Top view of a flower enlarged about 16X. This flower was slightly deformed. Here only two coronal scales are shown, rather narrow and sharply keeled down the back dorsal side). The outer apex exceeds the (deeply cut) corolla sinus and the inner lobe reaches the center. The outer lobe rises sharply and descends toward the inner apical area. The corolla outside is glabrous whereas the inner surface is thickly pubescent especially the apical areas. The corolla is reflexed. Here as the flower is mature the lobes of the corolla turn inward.

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Hoya endauensis Kiew 1989

View of the corona on the corolla enlarged about 8X. The inner coronal lobes are triangular spatulate with a short ridge on the dorsal surface. Outer lobes are obtuse, thin and here cupped inward, that may be due to slight drying of the flower ? Coronal scales are sway backed . Again note the circular buttery colored spot on the lower corolla lobe. The anthers are exposed in the center, membranous. Here the stylar crown in showing in the center of the corona, it is capitate in structure. Lower view of a corona enlarged about 16X. Surfaces are glabrous, skirt is cleft below the anther wings. there is a thickened central 0.07 cm. long, column opening 0.06 cm. (ovary cavity). Apex – apex Apex – center Widest

0.09 cm. 0.10 cm. 0.10 cm.

Another view of the flower and central corona that is relatively small. outer lobes obtuse turned inward, anther crown in center exposed.

An individual scale enlarged about 32X. Mostly showing the obtuse rounded, thin outer coronal lobe. Inner lobe here not clearly delineated.

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Hoya engleriana Hosseus 1907

Bottom view of the corona enlarged about 16X.The column here is prominent and thickened, lobes are channeled below, there are narrow side lobes which meet at the outer apex which them form the typical indented end of this subsection of Acanthostemma. The subsection is designated as Angusticarinatae Kloppenburg.

Top view of the corona enlarged about 16X. Here the outer lobes are rounded and with the typical indentation formed when the narrow side lobes meet at the end, the back is slightly swayed and the inner lobes are raised and do not reach the center. These inner lobes are rounded and short, not spatulate nor dentate. The side lobes arise from just below the retinaculum area on the sides of the coronal lobes and extend to the outer apex.

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Corona: lobes well short of reaching the corolla sinus, inner lobes do not reach the center, short, elevated slightly, rounded. Rudimentary side lobes on lower edge of coronal lobes do not exceed the apex but do form a groove at the outer apex on the lower side. Below channeled. Center to apex Apex to apex Widest Ret. - ret. Ret. - center Aw. - aw. Aw. - center

0.29 cm. 0.33 cm. 0.16 cm. 0.07 cm. 0.11 cm. 0.17 cm. 0.15 cm.

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Hoya erythrina Rintz 1978

Top view of the corona and corolla enlarged about 8X. The coronal lobes exceed the corolla sinuses, The corolla is glabrous outside and pubescent inside, made up of short ciliate cells. The corolla lobes are rolled under; it is cut about 3/4 the way to the center .

Top (left) and bottom (right) views of the corona enlarged about 8X. The inner lobes are dentate and do not reach the center so the anthers are exposed. The center is raised, the dorsal is domed and somewhat keeled, tapering outward to an acute angle and the apical area is raised. There are narrow side lobes which places it is the subsection Angusticarinata Kloppenburg. Below it is channeled to opposite the sinuses, the surfaces are finely sulcate all over. Anthers are long. Apex to apex 0.30 cm. Center to apex 0.35 cm. Widest 0.15 cm. Ret. to ret. 0.10 cm. Ret. to Center 0.09 cm. Aw. to aw. 0.16cm. Aw. to ret. 0.07 cm.

Side view of an individual scale enlarged about 8X. Inner lobe is raised dorsal is swayed and the outer lobe is raised. The rudimentary (narrow) side lobes are visible about in the middle of the profile, they do not reach the outer apex.

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Hoya erythrostemma Kerr 1939

Bottom view of the corona enlarged about 16X, glabrous with lobes channeled to just inside the sinuses with channel lobe ends rounded, lobes long and narrow. Apex – apex

0.38 cm.

Top of the corona enlarged about 16X. Lobes are sharply keeled and extend nearly to the center, glabrous.

Side view of a scale enlarged about 32 X. Scale is very thick 0.20 cm. deep. anther wings deeply scythe shaped. narrow side lobes along the lower edge reaching the outer apex. Emarginate a character of Subsection Angusticarinata of the section Acanthostemma. Inner lobe short spatulate, anther a little longer

Stylar crown greatly enlarged it is very similar to those found on H. elliptica and H. mindorensis Rather ornate with narrow lobe like structures around the edges.

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A Second clone from Edward Gilding Bottom view of the corona enlarged about 16X.lobes are channeled with tightly rolled edges not sulcate, very smooth, apex acute, large central column, thickened.. Color dark red, glabrous Column short 0.07 cm.

Side view of a coronal scale enlarged at least 16X. Inner apex turned up but lower than the dorsal, lobe thick and plump outer apex is emarginate, anthers a little exceeding. surfaces glabrous. Anther wing deeply scythe shaped. Scale depth 0.30 cm. Top view of the corona enlarged about 16X. Lobes are sharply keeled above but do not quite touch in the center as H. mindorensis Schlechter does. Apex – apex Apex – center Ret. – ret. Ret. – center Aw. – aw. Aw. – ret.

0.43 cm. 0.45 cm. 0.12 cm. 0.14 cm. 0.25 cm. 0.11 cm.

Stylar crown greatly enlarged with a cone shaped mealy top and linear side lobes, typical of H. mindorensis. A species I have made this sp. synonymous with.

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Hoya excavata Teijsmann & Binnendijk 1863

View of the top surface of the corona at about 16X. The inner lobes are short, neither dentate not spatulate, they do not reach the center so the anthers are plainly visible. Outer lobes are obtuse, center dented with a prominent umbo in the center.

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Bottom view of the corona enlarged about 16X, Note the thickened column, the central cavity that held the two ovaries and the fact that the short broad scales are channeled from apex almost to the collar.

With one coronal scale removed the five-sided staminal column is visible in the center. Over most of the history of hoyas this central peak was referred to as the stigma. The actual receptive areas of the stigma are located under the corners of this table and form a groove or split above where the retinaculum is secreted. There may be some taxonomic value to the staminal column since there is variation in shape and configuration among the species.

Side view of a coronal scale enlarged approximately 16X. The scales are essential horizontal with a slightly elevated inner lobe, which is very short, extending beyond it is the anther. Note how the anther is thickened to form one side of an anther wing, which provides an avenue to the stigma, or path along which the pollinia can slide, once in place. (here it is the lighter curved material on the lower forward part of the scale), to the right, attached forward of it, is some spongy columnar material. Corona: a umbo 2/3 in from the outer apex, outer apex obtuse, round; inner lobe acute, short but not dentate, top finely sulcate. Apex - apex 0.32 cm. apex - center 0.37 cm. widest (top) 0.20 cm. Retinaculum - ret. 0.13 cm. Ret. - center 0.12 cm. Anther wing - aw. 0.27 cm. Aw. - center 0.22 cm.

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Hoya faoensis Kloppenburg & Siar 2008

Inside view if the flower enlarged about 8X. Corolla surface is puberulous. Coronal lobes almost reach the corolla sinuses. Inner lobes are tapered and long, very stiff, touch in the center and cover the anthers. Outer apexes are narrowly rounded, tapering from the middle to the apex. Center raised a little, scales nearly horizontal otherwise. Dorsal edges are sharp, slightly concave, longitudinally sulcate. Bottom view of the corona enlarged about 8X. All surfaces glabrous. Lobes are channeled. Apex - apex and Center Widest Anther wing - aw. Anther wing - center Retinaculum - ret. Ret. - center

0.32 cm. 0.15 cm. 0.14 cm. 0.13 cm. 0.07 cm. 0.05 cm.

Side view of a coronal scale enlarged about 16X. Inner lobe is narrowly rounded and raised, scale is not overly thick in depth. Outer apex slightly sloping downward but dorsal surface is essentially horizontal. Anther wings are not deeply curved nor much thickened.

Corona enlarged about 16X showing the small domed stylar crown after 2 scales have been removed. On the inner apex of the upper right side of the lobe the curved (yellow) anther wing is plainly visible. The dorsal surfaces of the scale upon drying a little, seem to have two longitudinal ridges one down each side of the scale. Outer lobe apexes appear to be emarginate.

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Hoya ferrerasii Kloppenburg & Siar 2010

Corona: dorsal scale concave, with forward umbo, inner lobe finely dentate does not reach the center, lobes exceed the corolla sinuses, outer apex acute, corona flat, anther wings and retinacula plainly visible. Channeled below with sides rolled under, diagonally sulcate, center with a collar, thin up to 0.06 cm long. Enlarged about 11X.

Apex – apex Apex – center Widest Ret. – ret. Ret – center Aw. – aw. Aw. – center

0.29 cm 0.29 cm 0.12 cm 0.07 cm 0.06 cm 0.15 cm 0.15 cm

Side view of a coronal scale enlarged about 28X. Anther wing is fairly deep scythe shaped. Also the outer lobe apex is raised.

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Hoya fetuana Kloppenburg 2003

Inside view of the flower enlarged about 8X. Corolla surface is marginately pubescent and covering most of the lobe otherwise glabrous. Corona center raised with inner lobes spatulate touching in the center, glabrous. Outer apex emarginate, rounded. Apex - apex Widest Anther wing - aw. Aw. - center Retinaculum - ret. Ret. - center

0.40 cm. 0.15 cm. 0.20 cm. 0.20 cm. 0.10 cm. 0.08 cm.

Lower side of the corona with 2 lobes remover, enlarged about 8X. Lobes are channeled all the way to the short central column. Lower side lobes are rather flat and extend to the outer apex. Anther wings are narrow and protrude.

Coronal scale side view enlarged about 16X. Inner lobe raised, dorsal almost horizontal, cupped a little with a domed ridge down the center; anther wings fairly deeply curved.

Top view of the corona showing the stylar crown enlarged about 6X. Crown in a mealy dome.

Stylar crown.

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Hoya finlaysonii Wight 1834

Side view of the flower enlarged about 16X. Corolla reflexed and a pale yellow with Mahogany flush on lobes. Corona nearly flat, white in color, outer apex emarginate due to narrow side which originate well down on the scale, below the anther wings, lobes extending to the apex. Scales channeled below.

Bottom view of the corona enlarged about 16X. Lobes channeled, loosely open near outer apex and slanting to the base of the anther wing extensions, surface is

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beautifully finely sulcate, outer lobes are rounded, anther wings are thick and double. Column is short and rather thin walled.

Top view of the corona enlarged about 16X. Inner lobes are very small and dentate, they do not reach the center where the anthers are exposed. Side view of an individual scale enlarged about 16X, outer apex emarginate, inner lobe dentate and short, anther projecting beyond, anther scutellar and deep. Top almost horizontal.

Corolla: reflexed yellow with maroon flush on coronal lobes especially on inner surface. lobes deeply cut, apex acute, outside crystalline glabrous but granulose, inside with a very fine pubescence. Sinus to sinus Sinus to apex Widest Center to sinus Center to apex

0.45 cm. 0.50 cm. 0.50 cm. 0.35 cm. 0.80 cm. flattened, so flower diameter is 1.60 cm.

Data above from clone collected in Southern Thailand

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Below data and pictures from another clone of Southern Thailand labeled "Pale".

Bottom (left) and top (right) view of the corona enlarged about 8X. Here the anther wings are not doubled, the outer apex is more elongate and more acute, inner lobes are longer, groove below (curved lobe sides) extends inward toward the center further. Lower side lobes present in both, and both have a well developed and thickened central column.

Top view of the corolla and corona enlarged about 8X. The outer apex exceeds the corolla sinus. The dorsal surface of the coronal lobes is slightly concave with raised edges and an umbo and broad keel starting just outward from the dentate inner lobe and extending to the outer apex.

I left this top view of the staminal pentagonal crown at 100% so it is not in proportion to the immediately above photos here it is enlarged about 16X. There is still 3 pollinarium affixed to the corners of the table. The central rise is simple (here light yellow).

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Corona: lobes exceed the corolla sinus, crown outer apex slightly angular, otherwise horizontal, cupped centrally edge with linear ridge, inner lobe short, toothed (dentate). Anther exceed side lobes channeled sides overlap and are linearly sulcate. Apex to apex Apex to center widest (top) Anther wing to aw.

0.37 cm. 0.40 cm. 0.17 cm. 0.255 cm.

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Hoya fischeriana Warburg 1904

Bottom view of the corona. The scales do not appear to be channeled, glabrous but granulose here, not sulcate. Anther wing apical area very prominent, grooved below, reaching almost to the central region.

Top view of the corona. Scales broadly ovate, outer apex obtuse shortly apiculate, inner lobe extended, spatulate does not reach the center anther wings very prominent, sides doubled, groove prominent. Protrude beyond the corolla sinuses by 0.06 cm. Apex – apex Apex – center Widest

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0.34 cm. 0.40 cm. 0.20 cm.

Inside view of a flower. Corolla inside puberulous, outside glabrous, very thin. Sinus – sinus Sinus – apex Apex – center Widest Aw. end width Aw. exposed depth

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0.27 cm. 0.55 cm. 0.85 cm. 0.45 cm. 0.13 cm. 0.14 cm.

Hoya fitchii Kloppenburg & Siar Bottom view of the corona. Lobes are channeled to area in from the sinuses, lobe lower surfaces are glabrous and diagonally sulcate. Anther wings are thick and protrude beyond sinuses, Center is a thickened walled short column.

Top view of the corona. surfaces glabrous. Inner lobe is short, dentate, does not reach the center, dorsal surface is slightly concave with a forward raised area and also a raised area in the median near outer apex which has a somewhat blunt apex. Apex – apex 0.30 cm. Apex – center 0.33 cm. Widest 0.12 cm. Ret. – ret. 0.10 cm. Ret. – center 0.09 cm. Aw. – aw. 0.20 cm. Aw. – center 0.17 cm. Outer apex – outer apex on adjacent scale 0.38 cm.

Inside view of a flower. Coronal lobes reach or exceed slightly the corolla sinuses.

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Side view of a coronal scale greatly enlarged. Picture not very clear shows a raised inner lobe with dorsal surface nearly horizontal, outer lobe apex rounded. Scale not exceptionally deep with anther wing scythe shaped., all surfaces glabrous.

A single scale showing the dorsal slightly concaved surface, raised inner dentate lobe, with anther exceeding it.

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Hoya flagellata Kerr 1940

Bottom view of the corona enlarged about 8X. Lobes are channeled to near the central long thickened column; and sides are sulcate. Apex is acute. Column is 0.10 cm. long 0.02 cm. in diameter.

A group of flowers top view showing flowers opening with the long corolla lobes recurved and the very long flagellate anthers extending from the flower center.

Side view of a corona with the long central anthers. Apex – apex 0.27 cm. Widest 0.12 cm. Ret. – ret 0.07 cm. Ret. – center 0.07 cm. Aw. – aw. 0.12 cm. Aw. – center 0.16 cm.

Staminal center column has a sub-capitate head, crystalline-granulate texture, not divided as in Type description.

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Side view of an individual coronal scale enlarged about 16X, Inner lobe is thick dentate, outer lobe is acute but rounded. Anther is extremely long and narrow with an acute apex. Anther wings are narrowly cupped.

A greatly enlarged photomicrograph of the surface of the anther extension showing the textured surface.

The apex of a coronal lobe showing the channeled beginning at the apex and the linear sulcate surface, normally in Hoyas the sulcations are diagonal curving over the sides to the channel.

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Hoya forbesii King & Gamble 1903

Inside of flower enlarged about 16X, coronal lobes are small and do not come near the corolla sinuses.

Bottom view of the corona enlarged about 16X. Lobes are channeled to about even with the sinuses, edges plump and fully rounded and sulcate center has a short thick-walled column., anther wing apices are acute with side lobes made up of shelves on the lower edge of the corona lobes, outer apex is emarginate.

Bottom view of the outer apex displaying the emarginate obtuse apex, a result of rudimentary side lobes meeting at the apical end.

Enlargement of the sinus area ventral side of scale. Anther wing apex protrudes a little from the sinus and has a side protrusion at the beginning of the rudimentary side lobes visible just out (above) from the apex. To the right is the thick walled central column.

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Top view of the corona greatly enlarged. Scales are plump with rounded surfaces, essentially horizontal with inner apices raised a little, said to be an “erect tooth” but actually spatulate, they do not reach center, dorsal with a low keel from apex to apex, outer lobe obtuse emarginate. Apex – apex Apex – center Widest (below) Ret. – ret. Ret. – center Aw. – aw. Aw. – center

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0.28 cm. 0.28 cm. 0.15 cm. 0.10 cm. 0.06 cm. 0.28 cm. 0.21 cm.

Hoya fraterna Blume 1849 View of the ends of the coronal lobes enlarged about 8X. The lobes below are channeled with the outer lobes raises exposing the channel, Central anthers are crepe-like in an unusual manner.

Top view of the corona enlarged about 8X. Lobes channeled below, outer apex raised above the center and obtuse. Inner lobes with dorsal keel imbedded in the anthers not quite reaching the center, I suspect, dentate. Anther wings narrow but prominent.

End view of the corona enlarged about 8X. The outer surface is sulcate around the channel. 0.48 cm. from the apex to wings on inner side of channel. Anther wing – aw. 0.20 cm. Column about 0.07 cm. tall with a 0.24 cm opening, very fine hairs about the base.

Anther enlarged about 16X. Normally anthers are triangular with an acute apex in most hoya species. Here the apex is rounded, surface crepe-like. The pollinia pockets (2) are at the base on either side of the dark central thickening.

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Hoya fungii Merrill 1934

Side view of the corona enlarged about 16X.. There is lots here to see. The white anthers at the center rise prominently above the dentate inner coronal lobe (here red in color); sloping outward the outer apex is knobbed slightly because of the narrow side lobes extending to this apex. The dark Retinaculum is visible and below it the anther channel. The coronal lobes are relatively thick.

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Bottom view of the corona enlarged about 16X. The lobes on this side are channeled. There is a pink stain at the base below the anther slot opening. The surface does not appear to be sulcate, rather it is smooth.

Top view of the corona enlarged about 16X. Here the anthers at the center are folded back a little. The inner dentate lobe rising toward them has a slight ridge down the

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center. The scale surface is glossy, small side lobes can be seen starting just below the inner lobe and extending along the scale side.

View of the stylar pentagonal table with a simple domed center. Enlarged about 16X. Two anthers remain one erect to the left and one bent to the right of the table, to the lower right an anther is completely bent over and the pockets where the pollinia lay are visible also one pollinarium to its right.

Side view of a coronal scale enlarged about 8X, as stated before this scale has a more elongated and narrower outer lobe, the extended side shelves cause the outer apex to be emarginate.

Apex - apex Apex - center Widest Ret. - ret Ret. - center Aw. - aw. Aw. - center

0.35 cm. 0.37 cm. 0.20 cm. 0.07 cm. 0.09 cm. 0.20 cm. 0.20 cm.

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Hoya fuscomarginata Brown 1910

Bottom view of the corona enlarged about 8X. The surfaces are finely sulcate the lobes are channeled well in toward the center, there is only a very short column, outer lobes are acute tapering from near the anther wing area.

Top view of the corona and corolla enlarged about 8X. Inner scale lobes are rather short, do not reach the center and are rounded to slightly dentate, 0.35 cm. long. Dorsal surface is rounded and keeled from apex to apex, widest in the anther wing area, 0.175 cm. Outer lobes are narrowly rounded and just barely reach the corolla sinuses.

Side view of the coronal scale enlarged about 16X. Scale sloped to outer apex, which appears to be emarginate. Inner apex is raised, short and sub-dentate, it does not reach the center and the anthers are well exposed. Here there is one pollinium showing. Anther wings are curved shaped.

Side view of the stylar table. To the left is a coronal scale pulled back and inward an anther with a pollinarium still attached. The stylar center is a raised narrow dome.

Corona: 0.70 cm. in diameter, 0.18 cm. at widest, scales 0.32 cm. long. 152

Hoya gigantangensis Kloppenburg 1992

flowers from the type herbarium sheet

Bottom view of the corona enlarged about 8X. This surface is channeled, side lobes are sulcate. Slight column in center. Anther wings rather thick.

Flower inside view enlarged about 8X. Center of corona is very upright and outer lobes extend at right angles to the central axis. Bi-lobes are wide, sulcate, flat on top and extend well beyond the coronal lobes outer apices. Inner lobes rise above the anthers but do not cover them. Outer apex does not reach the corolla sinuses.

Top view of the flower enlarged about 8X. The reason I feel this may be the above species is the upright center to the corona and the flat surfaced bilobes, almost horizontal, also the leaves, peduncle and rachis are similar. It seems the bilobes here are extremely long, extending considerably beyond the outer apex.

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Another view of the flower enlarged about 8X. Here the corolla lobes are extended so the rather apiculate apex can be seen. I did not note this minor variation on the original, however the apex of the calyx on the type was also apiculate. The coronal lobes reach the corolla sinuses. The thick pubescent upper corolla surface shows well.

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Hoya gildingii Kloppenburg 2001

View showing the apex of the stylar table with surrounding coronal scales (3) enlarged about 14X. The cleaver-like knife edged inner lobes are clear in this photo. Anther wings creped and cover the stylar table but are below the height of the inner coronal lobes. Corona: Apex - apex Apex - center Ret. - ret. Ret. - center

0.40 cm. 0.46 cm. 0.11 cm. 0.12 cm.

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Two views of the corona enlarged about 16X. Again showing the knife edged inner lobe the keeled edges of the dorsal surface of the lobes with the outer apex turned down. The retinaculum is well in from the outer end of the anther wings.

Under side view of the corona enlarged about 16X. The lobes are openly channeled, the groove extending only a short way inward. The central column is thickened and about medium in length. 156