PS-TheHoyan

Vol. 12, #4

September 1, 2012

 

 

 

 

Hoya acuta Haw.  Rev. Pl. Succ.  4 (1821).

Hoya amoena Bakh. f.  Blumea  6: 380 (1950).

Hoya lanceolata Lindl., Donn’ Cat. Edit. 11 92 (1826), non Wallich ex D. Don (1825).

Hoya ovalifolia Wight et Arn. ex Wight  (1834), non Hoya ovalifolia Wallich (1847).

Hoya parasitica Wallich ex Traill  Trans. Hort. Soc. VI, 23 (1830).

Hoya purpureo-fusca sensu Koord. (1912), non Hook. (1850).

Hoya rumphii Hort., non Blume (1827).

Hoya albens J. S. Miller ex J. Traill, Trans. Hort. Soc. London  7: 23 (1827), nom. Syn., J. S. Miller ex

Steudel, Nomencl. Bot., ed. 2(1): 777 (1840).

 

 

           You will note that I have not included Hoya verticillata  in the synonymy above.  That is because I no longer believe that Hoya acuta and Hoya verticillata are the same species.  I base this on Vahl’s published description of his Sperlingia verticillata.  He described the foliage’s venation as being “avenia, enervia.”   That means “without veins, without nerves.”  Of course we know that all plant leaves have veins and nerves and that what Vahl meant was that the foliage of  his species appeared to lack veins and nerves.  I’d like to remind you, also, that Vahl was describing foliage on a dried herbarium specimen.  That is, if Vahl actually had anything to do with the description as the name Sperlingia verticillata  wasn’t published until 6 years after Vahl’s death.  The account I read was that he was hung for the crime of treason. 

The veins and nerves on dried specimens tend to appear a lot more prominent than those on living plants,  Vahl  (or whomever published it in his name) didn’t see any.  While, I know that the flowers are the most important feature in hoya identification, I just don’t see how anyone can overlook the obvious.  There isn’t a single plant being sold and distributed as Hoya verticillata that is minus very conspicuous veins and nerves.  Those veins and nerves are not even of the same pattern found on Hoya acuta leaves.  There are very obvious differences in the flowers also. 

           There are still other Hoya names that may or may not be synonymous with Hoya acuta  and with Hoya verticillata.  All of us are likely to be sold another with a different name, sooner or later. Some day, there will be a cheap and quick way of identifying these plants.  Considering my age, I’m not likely to be around when that happens, but if there is a way after I’m gone, I’ll be spooking those in the hoya world until they finally get it right!

 

 

Hoya acuta Haw. (IML-1038).  Aka as Hoya sp. Bangkok 2.

 

           David Liddle’s thoughts on this subject:

                                                           In a letter dated 27, March 2008, David wrote, “I would call  Bangkok #2 Hoya acuta. “  He went on to a comparison of this with Hoya pottsii, which, at that time some were confusing  with Hoya acuta.  Some still confuse the two.  He said, “My interpretation of Hoya pottsii against Hoya acuta is from leaf venation and corona shape.  These two species groups are easily separated on the margins of their distribution but get a bit muddled in South Thailand.

           In Hoya acuta the predominant venation leaves the midrib at right angles and the outside vein is not straight, for want of a better word, as in Hoya pottsii.  The corona lobes are narrowly ovate.  Hoya acuta starts in South Thailand and is present in Borneo and peninsula Malaysia.

           Hoya pottsii  has the predominant veins starting at the base and do not loop from auxiliary vein to auxiliary vein.  They have a network of veins on either side of them.  The corona lobes are more broadly ovate than in Hoya acuta.

           I also support the position that Hoya acuta is the same as Hoya parasitica.  Hoya acuta has precedence.”

 

My own conclusion regarding the so called Hoya acuta bronze (or as Kloppenburg calls it acuta bronce) and Hoya acuta green is that neither one of them is Hoya acuta. I have several sets of microscopic photos of the flower parts of that pair and they simply do not match those of Hoya acuta. I also have microscopic photos of the two variegated hoyas that are circulating as Hoya acuta.  They are not Hoya acuta  either.  I suggest that you add the abbreviation “aff.” between the genus name, Hoya, and the species name acuta, when writing your labels and caution anyone you give or sell a cutting to that the “aff.” stands for the Latin word, affinis, which means “near,  related to;” or it could even mean that the two species share the same habitat. It does not mean that they are the same species.

 

It appears to me that the hoya featured by R. Rintz in his Malaysian Nature Journal  as Hoya parasitica best fits the Vahl publication of Sperlingia verticillata or Sperlingia opposita. This is one of those that Rintz described in great detail without having seen a type specimen. Rintz even cited two other hoyas as being the same (Hoya ridleyi and Hoya globifera sic- no such hoya).  His citation of the Hoya globifera publication made it obvious that the hoya he referred to was Hoya globiflora.

 

 

A Tale of Three Hoyas

 

         The following hoyas were imported into the US by the USDA in the 1960s or 1970s – exact date lost to me due to my copy of USDA’s Plant Inventory #178 being so long used and dog-eared that it has lost its cover where the date was recorded.

 

         These three hoyas were all found “in the hills above Patep 2 Village.”

 

Hoya calycina (USDA-354236)

 

Note that all the flowers’ corona lobes are well inside the corolla.  They do not extend beyond the place where two corolla lobes meet. The red stars’ lobes that extend from underneath the coronas are extremely long and extend, for the most part about a third way into the corolla lobes. Although the corolla lobes’ side margins turn downward that down turning is very slight and many of the lobes do not turn down at all.  Although this is frequently cited as being Hoya calycina subsp. calycina, I do not agree.  I could be wrong but it appears to me that the typical form is USDA-354237.  I could be wrong but I don’t think so!

 

 

Unnamed varietas or subspecies of Hoya calycina (USDA-354235)

 

           Note that the corona lobes of this one extend all the way to the crotch(or very nearly so)  where two corolla lobes meet.  Note also that the red stars peeking out from beneath the corona lobes are more like circles than stars.  None of the red extends into the corolla lobes.  Note too that not only are the corolla lobes a lot narrower than those on USDA-354236, all of them turn under, making the lobes appear even narrower. In my conditions, I found this to be the most reliable bloomer.

 

 

Hoya calycina subsp. calycina Schltr. (USDA-354237)

 

           It is my very biased opinion (based on a thorough examination of the flower parts and comparisons with the flower parts and foliage of Schlechter’s holotype specimen), that this one most closely matches Schlechter’s type and should be the one designated Hoya calycina subsp. calycina  Schltr.  It differs from the others, also, in having leaves that are much larger, some almost as large as a dinner plate.  The close up view of the flowers in my picture make the flowers look larger than the other two but they are actually slightly smaller than the other two.

 

 

Did You Ever Hear of Hoya ignorata?  Did You Think, “I must have that one?”

 

           I haven’t seen an actual plant of this one but, judging from the on-line illustrations I found, my opinion is:  “Save your money…. even if it’s only Confederate money or Monopoly money. That is the ugliest thing I’ve ever seen next to cow pies and horse hockey pucks!  I can’t imagine anyone wanting to grow it.  I’d not ignore it though.  If it grew in my yard, I’d be just as diligent in eliminating it as I do poison ivy!!!

 

 

Exposé of one eBay Seller:

 

I tried to tell him or her of these errors while the plants were still being offered but couldn’t find a place to click on and write to the seller.  Such a place has always been there before but I couldn’t find it today.   I didn’t make a record of who the seller was except to note  that this seller is always more likely to offer a mislabeled plant than a correctly labeled one.  Here are some of this seller’s offerings that I found on eBay (just about coming due) on August 7:

                                   #1:  A hoya that looked like it might be Hoya macrophylla being sold as Hoya microphylla.  The seller should buy a Latin/English dictionary.  “Macrophylla” means “large leaves.”   “Microphylla” means “minute leaves.”  The leaves of Hoya macrophylla  are often as much as 8 inches long by 4 or more inches wide.  The leaves of Hoya microphylla are only a little larger than a grain of rice.

                                   #2:  What appears to me to be an MM hybrid of  Hoya vitellinoides X Hoya incrassata (would need flowers to be sure) listed as Hoya meridithii (sic). Here the seller has misspelled meredithii and did not recognize that Hoya meredithii is a synonymous name for Hoya vitellinoides.  He or she also didn’t know that the featured hoya was not Hoya vitellinoides.

                                   #3:  Hoya diversifolia (or something similar) offered as Hoya fraterna.                                                       #4:  Hoya carnosa offered as cv. Dapple Gray.  The picture does not show the silvery “wash” on the leaves that one should expect to be on Dapple Gray.

                                   #5: Hoya latifolia offered as Hoya loyceandrewsiana.

#6: Hoya clandestina  offered as Hoya clandestine.

 

 

QUESTION:  Can you tell me about Hoya retusa?  It’s so unusual for a hoya because it only has a single bloom.  How did it get in with the hoyas? – Kim F.

 

ANSWER:  Last question first—It got in with the hoyas because it is a hoya, no doubt about it.  Number of flowers has nothing to do with determining a plant’s genus.  That is determined by the flower itself.  It is easy to see that it is a hoya because its flowers have five sepals, five corolla lobes, five corona lobes and five pollinaria.  Each pollinarium has two pollinia.  Pollinia are the hoya equivalent of the yellow pollen that  you see on the flowers of most other genera.

                 The number of flowers per umbel is variable.  One per node is the usual number but I’ve seen as many as 3 flowers both on my plant and on at least one herbarium specimen that I examined.  I tell you this so that you won’t think you have something different if yours should reward you with an extra flower now and then.

                Hoya retusa Dalz. was first collected by Nicholas Dalzell and published in Sir William Hooker’s Journal of Botany-Kew Gardens Miscellany vol. 4, pages 294 & 295 in 1852.

             

 Since then it has appeared in many other publications, such as:

                       Sir J. D. Hooker’s Flora of British India vol. 4, page 56 in 1883.

                       A. K. Nairhe’s  The Flowering Plants of Western India page 186 in 1894.

                       Gamble’s Flora of the Presidency of Madras vol. 2, pages 848 & 849, in 1923.

                       Saldanha, Cecil J. &  Nicholson, Dan,  Flora of Hassan District Karnataka, India  in 1976.

                       The Forest Flora of the Bombay Presidency and Sind, vol. 2, pages 257 & 258, in 1976… This one illustrated with line drawings. A photocopy of this was sent to me via e-mail, sans the author’s name.

                       The Handbook of Indian Flora, vol. 2, page 241.. No author’s name or date of publication available .  It was sent to me by same source as above.

 

QUESTION:  As you know, I am a big fan of miniature plants.  Proof is that I have purchased all of yours that I’ve been able to get you to sell to me.  I just saw one on eBay that I question.  It is offered today (August 15) as Hoya pallida by Aristea as a miniature hoya.  The picture just doesn’t look like a miniature to me.  What is your opinion?  … B. J. Donovan. 

 

ANSWER:  I (and just about every writer on the subject, for the past 100 years) have always considered Hoya pallida to be a synonymous name for Hoya acuta.    Not long before his death, David Liddle conducted a very detailed study of all the hoyas he could find that were circulating as Hoya acuta.  He then compared them with both original name publications and holotype specimens.  His determination was that Hoya pallida  is not, as previously thought, the same species as Hoya acuta.  Below is a picture of the hoya in his collection that David Liddle determined to be Hoya pallida.  It definitely is not a miniature. 

 

 

Hoya pallida (IML-1508)

Photo by David J. Liddle, used by his written permission.

Hoya pallida Lindl.  Bot. Reg. 951 (1826), non Hoya pallida Dalz. et Gibs. (1861).

 

           The ways this one differs from Hoya acuta are, 1).  Lack of visible leaf veins.  2). Larger mature leaves.  3).  Flower colour, these being truly “pale” as the name implies and as the author described them, while those of Hoya acuta  are quite vividly coloured and the leaf veins are very conspicuous

 

 

Looking for a good book about hoyas?

 

It doesn’t cover every hoya in circulation today but it is the only hoya book I know about that is almost 100% accurate.  It is a beautifully illustrated, scholarly written book that should, in my biased opinion, be in every hoya lover’s library. 

           To order a copy, contact the authors, Anders Wennstrőm and Katerina Stenman at anders.wennstrom@adm.umu.se for current price and to order a copy.  He assured me in a recent letter that he has plenty of copies left.

        

 

SRQ Hoyas –

 

A correspondent asked me about this seller’s hoyas.  She wanted to know how accurate her labeling is.  I checked the URL given me and can only say that, for the most part, I’ve no idea.  The pictures are too small to even be sure most of them are hoyas.  One thing I’m sure of because my correspondent sent me a really good picture of one she got from this seller.  It was mislabeled Hoya macgregorii.   I am 100% certain that the hoya sold to my correspondent as Hoya macgregorii is NOT that species.  I find it mind-boggling that anyone could confuse a small tri-nerved leaf plant with a plant having loose umbels of tiny flowers (the entire umbel only measures about ½ to ¾ inch in diameter) with that plain, pinnate veined leaf thing with umbels of flowers the size of  a tennis ball.  SRQ, it doesn’t help you to have the permission of your sources to quote them if the “facts” they are so willing for you to quote are as false as a three dollar bill!  If you want proof that what you have is not Hoya macgregorii, let me know and I’ll send you copies of both the original publication and a picture of the holotype specimen.

 

 

IML-1081

 

Did  you ever get this hoya from me or from any other source?  I got it from the Liddle’s many years ago.  It was labeled Hoya patella.  Some time after I got it, David Liddle told me that he was sure that it was not Hoya patella but he didn’t know what it was.  It grew beautifully for me for quite a long time but eventually it died, seemingly overnight.  It hadn’t bloomed for me before it died but had buds starting.  I liked the looks of the plant and wanted it even if it never bloomed.  I ordered a replacement from Iris and asked her, at the same time, if David had ever learned just what species it is.  She sent me a nice big cutting and told me that David had determined it to be Hoya megalaster.  So, if you got an IML-1081 from me (or from the Liddle’s before that identification was made), please change your labels.