J Syst Evol ›› 1986, Vol. 24 ›› Issue (4): 317-322.

• Research Articles • Previous Articles     Next Articles

Cypripedium subtropicum, a New Species Related to Selenipedilum

Chen Sing-Chi, Lang Kai-Yong   

  1. (Institute of Botany, Academia Sinica, Beijing)
  • Published:1986-08-18

Abstract: Cypripedium subtropicum S. C. Chen et K. Y. Lang is a phytogeographycally significant new species with its habit, inflorescence and column very similar to those of Selenipedilum of tropical America. It is found in Mêdog of southeastern Xizang, China. Its slender leafy stem bears at the summit a many-flowered raceme, amounting to 1.5 m in height. Although its ovary is unilocular—this is the reason why we place it in Cypripedium, the column characters resemble those of Selenipedilum. For example, the staminode is rather small and its long stalk is very similar in texture and color to the filament of the fertile stamens. Obviously, it is a primitive new species related to Selenipedilum based on the similarities mentioned above. In the subfamily Cypripedioideae, as generally recognized, Selenipedilum is the most primitive genus, from which or whose allies Cypripedium is derived. Of phytogeographical significance is the fact that Selenipedilum occurs in Central America and northern South America, while a cypripedium akin to it is discontinuously distributed in subtropical Asia. This suggests that Selenipedilum or Selenipedilum-like form be once continually distributed in North America and eastern Asia when the climate there was warmer, as it is in the subtropics today. The floristic relationship between Central America and subtropical Asia appears to be closer than expected, as shown by the distribution patterns of Tropidia, Erythrodes, etc. Based on the occurrence of all six sections and particularly the most primitive form in eastern Asia, Cypripedium seems to be of Asian, rather than Central American, origin. Selenipedilum possesses some very primitive characters, such as trilocular ovary, vanilla-scented fruit, seed with sclerotic testa, simple column and more or less suffrutescent habit. The latter is considered by Dahlgren & Clifford (1982) to be one of ancestral characters of monocotyledons, which is now very rare not only in Orchidaceae but also in all monocotyledons. It is indeed necessary to make further investigations on Selenipedilum and also the new species pub-lished here, as well as a detailed comparison between them.

Key words: Orchidaceae, Cypripedioideae, Sect.Subtropica, Cypripedium subtropicum, Selenipedilum, Cypripedium