WHAT IS THE PLANT? Phalaenopsis cornu-cervi ‘Pravit Chattalada’ received its JC award from the AOS in 1979 without my being required to obtain from an accredited taxonomist a certification of the correctness of its specific epithet (i.e.: cornu-cervi). Any such certification presumably also would have disclosed whether the plant was a recognized botanical variety or form of the species. It should be noted that, at the time, Seidenfaden’s description of Phalaenopsis thalebanii and his designation of it as a new species had not been published; in fact, the type specimen was not collected until 1983.
The foregoing situation gives rise to two issues that deserve some attention. First, how well does Seidenfaden’s description of Phal. thalebanii fit the morphology of Phal. cornu-cervi ‘Pravit Chattalada’? Eric Christenson, in his treatise Phalaenopsis, a Monograph (Timber Press, Portland, 2001:85), concludes that it does fit it, but I find that conclusion to be problematic, for reasons to be explained shortly. The second issue is whether Phal. thalebanii warrants designation as a separate species, or should it more properly be considered as merely a variety or form of Phal. cornu-cervi and given an infraspecific epithet? Christenson reached the latter conclusion. I believe the evidence strongly supports his position.
Seidenfaden formally described the type specimen of Phal. thalebanii in Opera Botanica, Number 95, 1988, Orchid Genera in Thailand XIV, (Copenhagen:241). He accompanied the Latin description with the following additional information: “This species, found in a single specimen near the Yaori Falls in the northern part of the Thaleban Sanctuary in September 1983 could at once be distinguished from Phalaenopsis cornu-cervi by the larger flowers with sepals and petals of a uniform cinnamon color with only indistinct darker spots. I discussed this plant with Dr. Garay and with Dr. Sweet, who took the view that that this must be considered a new species.” He also provided two line drawings, Figures 150 and 151: one of Phal. cornu-cervi, which he used as a reference point, and the other one of the type specimen of Phal. thalebanii. In addition, he included a photograph of a flower and bud of the type specimen (Plate XXVIb). The picture shows a faded, senescent flower with some faint spotting, but the spotting on the large bud, which appears to be in excellent condition, is very clear.
In Christenson’s Monograph, in which he expresses his disagreement with Seidenfaden’s designation of Phal. thalebanii as a new species, he states, “With some trepidation, I reduce P. thalebanii to the synonymy of P. cornu-cervi. … I do not think that the type of P. thalebanii is distinct at the species level from other Thai plants of P. cornu-cervi.” I know of no other taxonomist since then who has published a contrary view. Christenson ascribes much of the blame for Seidenfaden’s misclassification to his reliance on the line drawing of Phal. cornu-cervi, which Christenson is convinced has an explainable error that, when corrected, makes the drawing identical to the holotype of Phal. thalebanii; therefore, Phal. thalebanii is merely a form of Phal. cornu-cervi.
As for Seidenfaden’s Plate XXVIb, Christenson considers it to be inconsistent with the original holotype, although it is puzzling why Seidenfaden would publish the plate and specifically refer to it in his text if it were not a picture of the aforementioned “single specimen.” Some kinds of errors are difficult for an author to recognize in the process of preparing a manuscript for publication but that one, if indeed it was a mistake, does not seem likely to be of a kind that a botanist of Gunnar Seidenfaden’s caliber would fail to catch. Even if Christenson is correct about the picture, there is the text, in which Seidenfaden describes the flowers as “having only indistinct darker spots.” Regardless of the legitimacy of the picture in Plate XXVIb, Christenson would seem to have been rather remiss when he transcribed Seidenfaden’s “indistinct darker spots” into “without any noticeable markings.” Indistinct is not the same as not noticeable. Moreover, Seidenfaden’s formal description of the holotype, in Latin, describes the cinnamon color of the sepals and petals not as “uniform”, but as “paene constanti,” the English translation of which is “almost uniform.”
All of this is relevant to the issue of whether the cultivar Phal. cornu-cervi ‘Pravit Chattalada’ should have the infraspecific epithet f. thalebanii appended to its specific epithet, cornu-cervi. The flowers and buds of the Chattalada cultivar have no chartreuse ground color or picotee, and that much is consistent with the text of Seidenfaden’s description. However, they also do not have any spots or bars, an important feature that is at odds with a strict reading of Seidenfaden’s description. It is conceivable that Christenson was focusing on the absence of chartreuse ground color or picotee as governing consideration, rather than on the presence or absence of spots and bars. Even so, the difference between a form that has flowers that are almost a uniform red and one with flowers that are truly a solid color front and back, with no spots or bars whatsoever, should, one would think, be considered as being important enough from both a botanical and a horticultural standpoint to justify distinction between the two at the variety or form level (i.e.: to warrant separate infraspecific epithets). The solid color throughout the sepals and petals of Phal. cornu-cervi ‘Pravit Chattalada’ was deemed a unique and noteworthy feature when the plant was judged and received an award.
In recounting the history of Seidenfaden’s “single specimen,” Christenson states that “The holotype (original specimen) of P. thalebanii was collected in the Thaleban Sanctuary in northern Thailand.” Because of its relevance to the unknown original locale of Phal. cornu-cervi ‘Pravit Chattalada,’ I need to mention here that Christenson errs here in his geography. The Thaleban Sanctuary is not located in northern Thailand but in the small southernmost region of Thailand that borders the Andaman Sea and is adjacent to the northern tip of Malaysia. Christenson, in what was probably too hasty a reading of Seidenfaden, confused the northern border of the sanctuary with the northern border of the country Thailand. Unfortunately, his error has been repeated by a number of others who have cited him. Nevertheless, having said this, I believe Christenson’s explanation of why he thinks that Phal. thalebanii does not warrant species status is persuasive. In addition to the already mentioned considerations, he perceptively disputes Seidenfaden’s prominent assertion that the flowers of the type specimen of thalebanii are of exceptional size. Seidenfaden reported that the length of the lateral sepal of his holotype was 2.1 cm. That is not exceptionally large by any means. I reviewed the measurements of 15 AOS-awarded plants of Phal. cornu-cervi and found that ten of them had lateral sepals that were that long or longer.
Christenson’s references to plants of the thalebanii form in cultivation at the time of his writing in every instance pertain to the cultivar Phal. cornu-cervi ‘Pravit Chattalada,’ because at that time there was no other known clone in cultivation. Despite the geographical error and the one about absence of noticeable markings, Christenson, in my lay opinion, is completely correct not only about the proper classification of Phal. thalebanii but also in his explicit recognition that there is no evidence that Phal. cornu-cervi ‘Pravit Chattalada’ came from the “isolated, limited population at Thaleban.” I believe there now is good reason to believe that it did not come from that locale or population, as I will explain shortly. Phal. cornu-cervi ‘Pravit Chattalada’ most probably was collected in northern Thailand, not in southern Thailand. Sadly, recourse cannot be made to the vendor who sold us the plant at the market at the Royal Hotel. She was murdered while sleeping on a bench not long after selling the plant. Pravit and I now regret that, in our excitement over the plant, we never asked her for any information at the time we bought it.
