Abstract: Cephalanthera calcarata S. C. Chen et K. Y. Lang, a new saprophytic species of Orchidaceae, is based on a specimen collected by R. C. Ching in 1929 from Yunnan (Yangbi County, 25'38' N 100 '00' E), China.This is apparently a rare species that has not been collccted again since then. Its flowers are erect and white, with a conical spur 2 -- 3 mm long at the base of lip, by which it can be easily distinguished from another saprophytic species, Cephalanthera austinae (A. Gray) Heller, which is endcmic to western North America. These two spcies are the only saprophytic members of the genus,but, as a matter of fact, there is little evidence of closc relationship between them according to their floral characters. In addition, its affinity with other Chinese Cephalantheras is still uncertain, though it shows some similarities to C. falcata (Thunb. ) Bl. and C. yunnanensis Hand.-Mzt. A. A. Heller has once proposed the segregation of C. austinae as a monotypic genus, Eburo- phyton, on the basis of its saprophytic habit and geographic isolation. However,the discovery of the second saprophytic, but distantly related, species in Asia bears a good evidence of independent derivation of the saprophytic membcrs from different autotrophic ancestors. Thus it appears that there is no sufficient reason for treating them as a separate genlls.

Key words: Cephalanthera calcarata