Vol. 11, #3

March 15, 2011


My Favorite Hoya --- Today!


            Actually, my favorite hoya (after Hoya nummularioides)  at any given moment is the hoya that has blooms open.  I only pick favorites when I have to choose between two or more species with flowers open at the same time.  This unidentified hoya was favorite longer than any that I recall as it had flowers from a single umbel open for over three weeks.  Most hoya flowers drop their flowers after only 4 or 5 days.


Hoya species from Kunming, Kina.


            Yes, I know I’ve featured this hoya on PS-TheHoyan before ---- and I’ll probably feature it here again because I have so many doubts about its identity.  I have seen so many different documents, pictures and claims made about it by both rank amateurs and by professional taxonomists.  I am convinced that there are at least 3, possibly more species circulating as this species.

This is one of the easiest to grow and most rewarding hoyas I have ever grown.  It was slow to initiate first blooms but once it bloomed the flowers remained longer than any hoya flowers I’ve ever seen.  The umbel shown above was more than two weeks old when the picture was taken.  The flowers did not open at the same time.  The first day I counted 3 open blooms;  the next day there were 2 more.  Each day a few more opened until there were more than 30 open at once.  That’s when the first to open dropped off.  Look carefully at the picture and you will see several flowers that have turned light brown around the edges.  I expected those flowers to be gone by morning but they weren’t in a hurry to go.  They remained two more days.  I think the brownish border was rather attractive even though it told me that those flowers would soon drop.  The above picture was taken on day 17.

            Others sell this one as Hoya revolubilis, however, I admit to being totally confused and that is why I keep featuring this species on these pages so often.  There is at least one other species that has been circulating as Hoya revolubilis and at least one other species circulating as sp. Kunming, Kina..


How Sp. from Kunming, Kina Differs from Hoya revolubilis


Hoya Revolubilis                                               Hoya sp. from Kunming Kina


Leaf Margins:   Revolute.                                                          Not at all revolute.

Leaf apexes     Very obtuse.                                                     Variable but mostly acute.

Leaf bases       Broadly cuneate or rounded.                             Narrowly cuneate – same width as petiole.

Leaf costa        Flattened above; prominent below.                    Narrowly recessed above;  prominent below.

Petiole:             Has 2 to 3 glands at apex, where it joins            No glands found there on my plant.

                                    the leaf base.


How Sp. from Kunming, Kina  is Like Hoya revolubilis


Hoya  revolubilis                                   Hoya sp. from Kunming, Kina


Corona lobe:                Long, narrow.                                       Long, narrow.

Outer apex:                  Acute.                                                  Acute.




Above left:  A fresh “sp. from Kunming, Kina flower.

Above right:  The same flower several days later, when almost dried.  The flower appears to agree with the Hoya revolubilis description but the foliage doesn’t agree at all.


To Muddy the Water


            In the fall of 2001, I was sent a picture labeled Hoya oreogena by Dr. Obchant Thaithong.  Dr. Thaithong did not write it up but gave me permission to use it in The Hoyan.  In her letter she said that Hoya revolubilis was a synonym for Hoya oreogena.  A copy of Dr. Thaithong’s picture follows (she did not send a picture of the foliage):



Above:  Dr. Thaithong’s picture that she labeled, “Hoya oreogena.” This resembles my “sp. from Kunming, Kina” but is more vividly coloured.  Also the corona lobes are broader, more turgid and unlike my “sp. from Kunming, Kina” appear to have a raised longitudinal ridge on the outer half of each lobe.


To muddy the water even more, shortly after the above picture appeared in The Hoyan (Vol. 23, #3), as Hoya oreogena, I got a package from one of my Swedish Hoya friends, Berit Carlgren.  The package held a very generous cutting of a hoya known only as “sp. from Kunming, Kina” and a page that appeared to have come from her hoya bulletin, Sydhoyan.  She didn’t say it came from that publication but the page was the same size, on same type of paper and in the same format as that publication.  Also in the package I found a vial of flowers which were said to be H. sp. from Kunming, Kina flowers. I was convinced, just by looking at the pictures on the page (credited to Lise Rastrup Larsen) that the page featured two different species.  I have been told by several people that only one species is pictured there.  Below, see two small sections of this page of pictures.  



Above left: A leaf of Hoya sp. from Kunming, Kina.

Above right: A plant with radically different foliage.  What is this species?  I don’t know.  The leaves look like those of IML-1513, which David Liddle told me was Hoya oreogena, though, at the time he told me it was that, he admitted that he’d not seen a type specimen and his plant had not yet bloomed.  Later on, he obtained excellent pictures of the holotype specimen and sent copies to me.  Those pictures convinced me that Hoya revolubilis  is not a synonym for Hoya oreogena.  I still do not know whether the flowers in the above picture are like IML-1513 flowers or not.  My IML-1513 hasn’t bloomed and neither had David Liddle’s the last time he and I discussed it.  One thing I do know and that is that the foliage of IML-1513 is NOT AT ALL like that of the foliage on the Hoya oreogena holotype specimen.


            I have a lot of pictures of the flower parts belonging to that vial of flowers labeled “Hoya sp. from Kunming, Kina flowers.”  Since that species finally bloomed for me, I now know that those flowers do not belong to the species at above left. I don’t yet know what these two species are but I am convinced that the one in my pictures is one of the most desirable of all hoyas.

            I have often been asked by churches of all denominations to teach crafts classes at their Vacation Bible Schools.  I’ve taught youngsters to make flower pots out of real clay and out of recycled jars, bottles and gallon bleach and vinegar jugs.  I always give them hoya cuttings to plant in their newly made pots.  I used to give them cuttings of  Hoya diversifolia.   It really isn’t a very pretty plant though.  The only things it has going for it are that it’s leaves are green (my favorite colour) and it’s practically indestructible.  I often joke that you can’t kill it with  sledge hammer or a Sherman Tank.  From now on, I’m giving youngsters cuttings of  sp. from Kunming, Kina.”   It’s among the very best and it’s just as easy to grow as Hoya diversifolia.  Please give one to a child you know!


New Species Names Published Recently


1).       Hoya ubudensis Kloppenb. et Yap in Asklepios 108: 7-8 (2010).    This hoya is said to be a native of Bali, Indonesia.  The authors compared this to Hoya limoniaca, a native of New Caledonia (an island at least 2 or 3 thousand miles removed from Bali, Indonesia.  The resemblance between these two species is just about as far apart.  The greatest dissimilarity is in the leaves.  Kloppenburg described the leaves as having cuneate leaf bases.  I might have believed him had he not included a picture of the holotype specimen in his publication.  That specimen has 7 leaves on it.  Every one of those leaves has a broadly rounded leaf base. There isn’t a single cuneate leaf base to be seen.

            The leaves differ in another way too.  Hoya limoniaca leaves are quinquenerved.  Hoya ubudensis leaves have pinnate venation.

            Kloppenburg’s claim that the pollinaria of Hoya ubudensis is like that of Hoya limoniaca only proves one thing and that is that one of the pictures he used in making this comparison was mislabeled….. Heck, both probably were mislabeled!

            This species is one of the “Plain Janes” of the Hoya Kingdom.  The foliage is not outstandingly beautiful.  The only thing going for it is that it’s green.  The flowers are (if the pictures are correct) a light to medium shade of yellow with reflexed corollas.  At two feet away, an umbel looks little different from about two dozen other hoya species but the others have lovelier leaves.


2).       Hoya nuuuliensis Kloppenb. et Siar in Fraterna 21(4): 14-17 (2008).  If I were a betting woman, I’d bet my last dime that this is Hoya pycnophylla.  I put my pictures of the two holotype specimens side by side.  They appear identical. Of course, it is possible that the flowers differ.  It would surprise me if they do.


 3).      Hoya what???   in Fraterna 21(4): 9-13 (2008). There you’ll find Hoya tamaleaaaea Kloppenb.

The author said it was named for Vaiuki Tamaleaa.  Note the spelling of that name.

            In Fraterna 23(2): 4 (2010), you’ll find the following “correction” of that species name. Hoya tamalcaanus. I don’t know the correct spelling of that honoree’s name but it is obvious that if his name is Tamaleaa, then the species name of tamalcaanus is misspelled and the “correction” needs correcting.

            What do I think about the species itself?  The picture on page 13  seems to me to be shouting, “Look at me, my name is Hoya australis!  I could be wrong but I doubt it!


4).Hoya ferrerasii Kloppenb. et Siar  in  Fraterna 23(4): 21- 23 (2010).  The text says that this is similar to Hoya bicolensis Kloppenb.  I’ve no idea what that species is.  I never heard of it and couldn’t find it in IPNI when I looked.  The colour picture of a living umbel looks for the world like IPPS/GPS-8845 which Kloppenburg and his buddy Ted Green have tried to publish as Hoya paulshirleyi,  but Fraterna pictures are, for the most part of extremely poor quality. Little can be learned from them


5).Hoya fetuana  Kloppenb.  in Fraterna 16(2): Cover & 1-4 (2003). I haven’t seen a living example of this.  I’ve had no flowers to examine.  I’ve never heard of anyone who owns this.  My best guess is that this is most likely a synonym for Hoya chlorantha var. tutuilensis. That is only a guess.  I could be wrong but I bet I’m not!


6). Hoya faoensis Kloppenb. et Siar in Fraterna 21(4): 18-21 (2008). I haven’t seen a living plant that looks anything like this one and I believe that the text describing this species is even more flawed than the others. I think it is because Kloppenburg doesn’t know the meanings of the words he uses.  For example, he described the leaves as  having leaf tips that are shortly apiculate (ending in a short abrupt point).  The tips are attenuate (gradually diminishing in breadth), not apiculate.  Also, he says that the flowers on the holotype specimen are “white, tinged with pink.”  My observation is that white flowers dry to appear yellow, yet the flowers on that herbarium sheet appear almost black.   Kloppenburg’s pictures of the flower parts are yellow.  I believe his leaf measurements are not anywhere near accurate.  Knowing the size of the typical herbarium sheet and comparing that with the size of his reproduction of it, I think it’s a safe bet to say that the leaves are at least 3 times larger than Kloppenburg noted in the text. I believe that Kloppenburg has mixed parts of more than one species here and, if so, it is not the first time he has done that.

                                                                                                           --- More to come next time.





            Recently I was asked, “If two plants look alike but have different scents, wouldn’t that mean that they are different species?”  I’m not sure but I think that  it could mean that but that it could also have no bearing on the subject.  I’d want a chemical analysis to identify what caused the scent.  If it proves to be the same, then it is likely that the two are the same species, all other things being equal.  If it proves to be different, then I think it is likely that we have two species.

            I don’t much trust scent as an identifying trait.  I used to but I’ve seen too many cases where the same  flower has been sniffed by several people and all of them described the scent differently.  For example, Hoya onychoides.  When mine bloomed the first time, I thought it smelled like an expensive French perfume.  I gave a blooming plant to one of our H.S.I. members and she said the flowers smelled like varnish.  I have heard people describe the scent of Hoya carnosa as smelling like honey.  To me, it smells like a sweaty, unwashed body that has been doused in cheap dime-store perfume.  I’ve read in old time journals that Hoya globulosa stinks.  I wouldn’t know.  I’ve only known two people who has ever gotten it to bloom.  One said it had no scent at all. The other one’s comment was, I liked the scent so I must have a mislabeled plant.”  Hoya graveolens was named for its alleged foul scent but  some who have bloomed it say they noticed no scent.  Of course it is possible (even likely) that the one who said he had bloomed Hoya oreogena has a mislabeled plant.

            One grower told me that she had noticed that how a hoya smelled to her depended on how long the flowers were open and what she had for dinner.

            I’ll believe scent is a reliable trait in hoya identification when someone identifies the chemical that creates the scent and provides us with a practical test that all of us could afford to buy to test our flowers.  Until hoyas become an important agricultural crop (not likely to ever happen), the money to support that  kind of research will be at the bottom of every governments’ and every philanthropist’s list of priorities.




Question 1:    What Hoya is Hoya chlorantha?








What is this one?  Without actual flowers to compare with holotype specimen, I can’t be 100% sure but it looks very like Hoya betchei  to me.


Question 2:  Mr. Green says that Hoya imperialis var. Rauschii has dark purple flowers.  I always thought that they were light coloured.  What is your take on this subject?

Answer:  I think Mr. Green is full of prunes!  Here is a picture of it.  Do those flowers look to be dark purple to you?

The above is the picture of Hoya imperialis var. rauschii  Regel.  This picture accompanied the publication of its name in  Gartenflora 4: 281, t. 133 (1855). Regel described the flower colour as “lacquer-red much paler than the typical Hoya imperialis.”


Hoya imperialis var. rauschii differs from Hoya imperialis var. imperialis (the dark purple flowered one) in another way.  Its leaves have wavy margins.  Those of Hoya imperialis var. imperialis  do not have wavy leaf margins.



Now I have a question.  How many of you have taken cuttings of Hoya kanyakumariana?  Did you notice anything extremely unusual about it?  I did.  The first person who sends me and e-mail telling me what I observed that I’ve seen on no other hoya and you get the prize of one small pot of Hoya kanyakumariana. If you already have it, we’ll find a substitute.


Coming next time… My thoughts on Hoya padangensis vs. Hoya uncinata.