PS-TheHoyan

Vol. 4, #2

April 1, 2005

 

 

Hoya incurvula Schltr. – Photo by George Slusser.

 

Letter #1:  Why does the new publication. Hoya andalensis Kloppenb. ((Fraterna  18 (1): 2 (2005)) look familiar to me? I know it is named for a place because of the –ensis suffix but I can’t find such a place on any map nor the name in any reference. Where is it? --- What I asked myself as soon as I saw it.

              Reply:  It didn’t take long to learn why it looked familiar.  It is one I’ve grown for more than ten years.  I have compared it and all its parts with Schlechter’s Hoya incurvula and have found them perfect matches.  It took somewhat longer to learn that there is NO SUCH PLACE as Andal so this hoya cannot possibly be from such a place.

              Mr. Kloppenburg alleged in his publication that the name Andalensis was “derived form (sic) the ancient name for the Island of Sumatrera (Sumatra).”  I searched through my own desk encyclopedia and a CD of Encarta’s Encyclopedia that came with my computer, hoping to find a clue as to how one could “derive” a place name like Andal from a word like Sumatrera.  I could find no reference to either Andal or Sumatrera.  I did learn that Sumatra was the “nucleus” of an ancient Hindu Kingdom named Sri Vijaya. That was back in the 8th century.

               I then wrote to David Liddle and told him that I am 100% sure that this plant is Hoya incurvula and asked him if he’d ever heard of Sumatrera or Andal.  He replied that he’d been growing & selling this species as Hoya incurvula for about twelve years.  He gave me an URL and said that he thought Kloppenburg must have gotten the name from that. I checked the URL and have been laughing ever since. I think that lad has something in his “pot licker” besides turnip juice and bacon fat!

 

Here is the URL: http://www.valdyas.org/andal/

              Take a look.  You’ll find that Andal is a figment of someone’s imagination!  Makes me wonder --- Did Kloppenburg intend this as an April Fool’s joke? Nah!  The joke’s on him! I’d surely like to know the author of that fiction – sounds like Stover!

 

 

Hoya incurvula Schltr. (syn. Hoya andalensis Kloppenb.)

Photograph by George Slusser.

 

REFERENCES:

 

Schlechter, R. Neue Asclepiadceen von Sumatra und Celebes, Geifhefte zum Botanischen Centralblatt 34(2): B 14(1916.

Burton, C., & Harold, Ken The Hoyan 12:20 (1990). Illustrated – Translation of above, with picture of type & Schlechter’s flower parts sketches.

 

Letter #2:  Perhaps I should call this “Letters” instead of “Letter” and add numbers into infinity because I’ve had a lot of questions asked about this one lately. The questions are all about a plant sold as Hoya ovalifolia. The most asked question is, “How soon will it bloom and what will the flowers look like?

              Reply:  My reply at this point is, “I don’t know.”  Up until a week ago I had not seen the plant in question.  A week ago I received a cutting of it in the mail.  The cutting came from about the coldest climate in the world next to the Polar Regions.  It was wrapped in newspapers and then in a two layers of that big soap bar sized bubble wrap.  When I got it, it had a sort of translucent look that frozen plants get but on feeling the leaves they felt dry instead of watery. 

              After leaving the post office, I had to stop at the grocery store so I took the cutting inside with me.  Publix gives free fountain Cokes to senior citizens.  I took mine, sans ice, and put that cutting in the Coca-Cola while I did my monthly grocery shopping.  It takes me an extra long time because I always make several trips around the store just for the exercise (I don’t do much walking in my neighborhood because I’m afraid of “Pit Bulls!”  My neighbors have a lot of them.  Well, to make a long story short, by the time I got home with that paper cup of Coca-Cola and that hoya cutting, it no longer looked frozen and now, one week later, the cutting is already rooted.  That’s about the fasted I’ve ever observed a hoya rooting. 

What is this cutting with the label of Hoya ovalifolia on it?  I really don’t know but I’m 99 and 44% sure it is not Hoya ovalifolia.   I’d guess that it might be Hoya hainanensis Merr., which some say is synonymous with Hoya ovalifolia. After seeing and examining an isotype specimen of Hoya hainanensis I am sure those saying it is a synonym for Hoya ovalifolia are wrong, because nothing about it “fits.”

 

 

I found the above specimen in the herbarium of the New York Botanical Garden.  It is Wight’s #1522, which Wight and Arnott designated as type of the species.

 

              What is generally overlooked, by most people like us, is that Wight appears to have mounted plant material from two different collections on this sheet.  The specimen on the right is Hoya ovalifolia.  It was collected in the “Neelgherry Mountains” of India.  The specimen on the left is from another plant, collected at Singapore.  In their publication of the name Hoya ovalifolia, Wight and Arnott (in the English part at the end of the brief Latin description) wrote, “The Singapore specimens are not in flower, and are probably different.”  Several years later, Joseph Decaisne quoted Wight and Arnott as saying that the two specimens “are different species.”  He did not cite any publication and I’ve been unable to find any documentation of their having said that but I think the two specimens on the above sheet speak for themselves.  If that isn’t enough, take a look at the following illustration:

 

The above illustration is from Robert Wight’s Icones Plantarum, tab. 847.

The leaves on both the type and the above illustration are definitely elliptic, which just proves that Wight’s definition of “oval” and my definition of “oval” are not the same.  Stearn agrees with Wight as he defines “oval” as “elliptic, i.e., broadest at the middle, the sides curved and length:breadth usually 2:1. (See page 459, 4th edition of Stearn’s Botanical Latin).

 

              Wight & Arnott’s published description was in Latin. They published it in 1834.  It was translated into English by George Don in 1837.  George Don’s translation follows:

“twining, radicant, glabrous; leaves fleshy, oval, acuminated at both ends; peduncles shorter than the leaves, many-flowered; corolla downy inside; segments ovate, acute; leaflets of corona oval, obtuse, with the inner angles short; stigma mutic. Native of the Neelgherry Mountains, and Singapore.  Hoya, Wight, cat. No. 1522. Wall. ascle. No. 31, 43,? and 45.  This is very nearly allied to H. parasitica.    George Don left off the English language statement cited above which Wight and Arnott appended to their Latin description.

 

              Please note that Wight and Arnott described the foliage as “oval, acuminated at both ends.” 

              Please note that the Neelgherry Mountain specimen of Wight’s has leaves that are acuminated at both ends.

               The hoya in Wight’s Icones Plantarum shows leaves that are oval-elliptic and acuminated at both ends.

              The Singapore specimen’s leaves are oval but just barely.  They are much closer to “round.”  They aren’t acuminated at either end. 

              The leaves on the cutting sent to me in the mail last week are very like those on the Singapore specimen.

 

              Note that the two umbels in the Wight illustration have about a dozen flowers showing but since only those flowers visible on one part of the umbel can be seen in a line drawing, I think it is safe to estimate that the full umbel must contain at least 25 to 30 flowers, yet Mr. Ted Green, from whom my source got the plant sent to me, described it in his catalog as having 15 flowers in its umbel. To be fair, I must say that this difference may not mean a thing.  It has been my observation that almost all of my plants of same species described by Mr. Green have two to three times more flowers per umbel than Mr. Green’s descriptions indicate they should have.

 

What do other authors have to say about Hoya ovalifolia?

 

Sir J. D. Hooker, in Flora of British India (4: 60, 1883), described the leaves as “elliptic or elliptic-ovate or –oblong or –lanceolate obtuse or acute, very thick, “-- which makes me wonder just what he was looking at when he described those leaves.

H. Trimen, in Handbook of the Flora of Ceylon (part 3; 162) described the leaves as “oval, tapering to a slightly rounded base, shortly acuminate, acute.”

Cecil J. Saldanha & Dan H. Nicholson, in Flora of the Hassan District Karnataka, India (449 - 1976), described the leaves as “elliptic, base acute to slightly obtuse, apex acute to obtuse or very slightly acuminate; margins undulate and not revolute.    I bold printed that to stress the fact that the cutting I got last week does not have a single undulation on the leaf margins and the leaf margins are very revolute.  The cutting I got last week also has broadly rounded leaf bases and its apexes are likewise, broadly rounded but with apiculate tips.  One leaf on the 4 node cutting even lacks an apiculated tip.  It is completely round.

              At US herbarium, there is a Cecil J. Saldanha specimen (15919) of this species collected by him in the Hassan District, Mysore, India in 1969.  It looks almost exactly the same as the Neelgherry specimen on Wight’s #1522.  The flowers on it are exactly as pictured by Wight in his Icones Plantarum, tab. 847.  I think the most remarkable thing about those flowers is the way the sepals overlap at their bases.  I have never seen another hoya with so much overlap of the sepal bases.  Another thing that impressed me was the very narrow and deeply divided corolla lobes (as in fig. 2 in the Iconnes Plantarum illustrations). Also, the corolla lobes on Saldanha’s specimen are long & narrow as those in Wight’s illustration.  In most cases, when I see corolla lobes that are long and narrow like that, they only look long and narrow because the lateral margins are rolled under.  In the case of the corollas on the Saldanha specimen, those corolla lobes are truly long and narrow. The margins on those flowers were not rolled under..

 

Wight and Arnott’s Neelgherry specimen shows that the leaves are arranged more or less in fascicles (verticiallate).    Note the two short branches with the whorls of leaves at their ends.  Those two branches show numerous scars from fallen leaves.  All of those scars are evidence of a large number of extremely closely spaced leaves.  I have never seen any other twining hoyas with so many leaves so closely spaced.  If it is true that Hoya verticillata is the correct name for Hoya parasitica,  then Wight and Arnott’s comparing their plant with Hoya parasitica  was right on the button!  The way I see that it differs from Hoya verticillata is that Hoya verticillata leaves are conspicuously veined, at least in the dry state.  That can be seen clearly in the pictures of the Hoya verticillata type specimen, furnished to me by Dr. Veldkamp of Leiden.

              One thing is very sure and that is that the plant that came to me as Hoya ovalifolia doesn’t even remotely resemble Hoya parasitica, whether you call it, Hoya verticillata, Hoya acuta, Hoya opposita or any other of the names people have appended to it over the years.

 

Some comparisons:

 

Leaves:

 

Wight: Ovate, acuminate at both ends. Margins undulate but not revolute.

Hooker f:  Elliptic, elliptic-ovate, oblong or lanceolate, acute at both ends.

Decaisne: Ovate, bases and apexes acuminate.

H. Trimen: Tapering to slightly rounded base, shortly acuminate, acute.

Gamble: Elliptic, elliptic-ovate, oblong or lanceolate, obtuse or acute at apex, margins not recurved.

Saldanha & Nicholson: Elliptic, base acute to slightly obtuse; apex acute to obtuse or very slightly acuminate; margins undulate and not revolute.  Saldanha’s specimen 15919 shows leaves that are acuminated and very acute at both ends,

 

Leaf veins:

 

Wight: Not mentioned in description but Wight’s illustration shows no leaf veins at all, except for the costa.

        Those on type specimen (from Neelgherry) are very difficult to see, even in the dried state.  Those on the Singapore specimen are easily seen in their dried state but they are not conspicuous. They are very straight and some appear to be almost at 90º to the midrib. Others are not quite so outspread but they are far from the oblique 45º noted by Saldanha & Nicholson (below).

Hooker f.: Nerves distinct.

Decaisne: Not noted.

H. Trimen: Not noted.

Gamble:  Main nerves, when dry, oblique, inconspicuous.

Saldanha & Nicholson: Lateral nerves oblique (about 45º).

 

I cannot say that the hoya now in circulation as Hoya ovalifolia is not that species but I don’t believe it is. We may be able to identify it correctly once it blooms of us.

 

NOTE:  To those who may see a hoya in Paxton’s Flower Garden labeled Hoya ovalifolia, Paxton erred.  That hoya is Hoya cinnamomifolia. Ditto to the plants described as this in L. H. Bailey’s Cyclopedia of Gardening, George Nicholson’s Dictionary of Gardening and second last edition of the RHS Dictionary of Gardening.

 

REFERENCES:

 

???, Forest Flora of the Bombay Presidency and Send 2:258 (1976).*

???, Flora of Ceylon 51 (1973).*

Decaisne, J., DeCandolle’s Prodromus etc. 8: 638 (1844).

Dietrich, Synopsis Plantarum 891 (date not available to me).*

Don, G. General System of Gardening and Botany 4: 126 (1837).

Gamble, James Sykes, Flora of the Presidency of Madras 2: 848 (1923).

Hooker, J. D., Flora of British India 4: 60 (1883).

Saldanha, Cecil J., & Nicholson, Dan H., Flora Hassan District, Karnataka, India 449 (1976).

Trimen, H., Handbook of the Flora of Ceylon, Part 3: 162 (date not available).*

Wight, R., Contributions to the Botany of India 37 (1834).

Wight, R., Icones Plantarum 847 (1843).

 

* Items with missing data were Xeroxed and sent to me by Kloppenburg several years ago.  I have been unable to fill in the gaps.

 

Here’s another URL for hoya lovers:

http://groups.msn.com/HoyasRUs