DIGITOSTIGMA OR ... ASTROPHYTUM?
Yuri A. Yudin (NH, USA)
A new Astrophytum with Jellyfish Head
In the Issue 2(18) we wrote about a recently discovered monotypic genus Digitostigma caput-medusae . Just a few months after this discovery, David Hunt transfers the plant into the genus Astrophytum . Hunt proposes to keep the existing species name of caput-medusae . Hence the current name of the plant is Astrophytum caput-medusae (Latin for "star-plant with jellyfish head "). Though flowers and seeds of Digitostigma are actually characteristic of Astrophytum (Photos 1 and 2), the plant itself is very different from any known Astrophytum . It resembles Ariocarpus agavoides or Leuchtenbergia principis (Photo 3). Below we are quoting some excerpts from the David Hunt's publication [1]:
"The authors of Digitostigma caput-medusae are to be congratulated on a truly remarkable discovery, but the feeling of our group is that its peculiar habit is not sufficient in itself to justify excluding it from Astrophytum , with which it shares unusual and significant features in common, i.e. the floccose indumentum and eccentric (hat-shaped) seeds, as well as having very similar flowers. Although the possibility is not ignored that it could be an ancient intergeneric hybrid, as has been suggested for the origin of Geohintonia , there is no evidence for this at present, and subgeneric rank within Astrophytum seems more appropriate:
Astrophytum subg. Stigmatodactylus D. Hunt nom. nov. Replaced synonym: Digitostigma Velazco & Nevarez, Cact. Suc. Mex. 47(4): 79 (2002). Type: Digitostigma caput-medusae Velazco & Nevarez l.c. 81-82.
'Digitostigma' not only controverses Linnaean canons for the formation of generic names but implies that the plant is notable for its finger-shaped stigmas rather than its spotted tubercles, contrary to the authors explicit intention. For this reason the opportunity afforded by the change of rank has been taken to provide an unambiguous name formed according to classical usage.
14215 Astrophytum caput-medusae (Velazco & Nevarez) D. Hunt comb. nov. B: 14214 Digitostigma caput-medusae Velazco & Nevarez l.c. 81-82. Type: Mexico, edo. Nuevo Leon, [locality withheld], matorral espinoso tamaulipeco, 100-200 m, 28 Aug 2001, Nevarez & Velazco s.n. (UNL 023704, holo.; UNL 023705 iso.)."
Propagation efforts
While botanists are still arguing about its position within the botanical nomenclature, we hope to see the plant in culture soon. Given the popularity of this species, there is no doubt that the plant will be intensively propagated upon its introduction in culture, and will quickly become common, as it had happened to Geohintonia . Considering its relation to the genus Astrophytum , we speculate that propagation of Digitostigma will not present significant difficulties, even for hobbyists.
The US section of the (Astro-Meister Group) reports about their reproduction initiative of A. caput-medusae in the United States. They have recently announced that seedlings of A. caput-medusae might be available to its members as early as by summer 2004 [2]:
"Our efforts in obtaining seed or seedlings of Astrophytum caput-medusae seem to be a success. Seсor A. M. Francisco of a renowned Botanical Garden near Mexico City told us about their reproduction project of the rare and probably endangered species. Seed is said to have been officially collected from several Caput-medusae populations in Nuevo Leуn by "workmates of Seсores Velazco and Nevбrez". Seedlings are grafted on top of Pereskiopsis and Echinopsis . The intention is a fast production of many offsprings. Seсor Francisco wants to give us 10 seedlings for a reasonable price. Additionally we have to pay for shipping & handling plus the quite high costs for CITES documents and phyto-sanitary papers (for U.S. Dept. of Agriculture). If our transfer of ten seedlings from Mexico to the U.S. works flawlessly, we're going to multiply our Caput-medusae stock in no time to get seedlings for all our members by summer 2004.
Latest information : We heard rumors about illegal collecting of Caput-medusae in their habitat. It is said that breeders in Vista/CA got their hands on illegal seed. Is that true? We don't know. Hopefully the Mexicans can protect this plant. The discovery of Geohintonia mexicana was a real nightmare for the species. We wish to let all of our members know: People who involve themselves in illegal plant trade cannot be members of Astro-Meister anymore."
More room for hybridization
It is very probable that there will be numerous attempts of hybridization of A. caput-medusae with the other species of the genus Astrophytum , and also with the species of Ariocarpus, Leuchtenbergia, Obregonia and similar genera. We predict that in a few years, our e-magazine will be publishing photographs of fascinating cultivars of A. caput-medusae , coming from Japan. Besides the aesthetic aspects of the crossing, the successes and failures of hybridization could help in better understanding the positioning of this new species in the Cactaceae family
Cultivar e-magazine will continue informing you about this interesting plant.
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