Abstract: Paphiopedilum malipoense S. C. Chen et Tsi is a very interesting new species with its flower similar to that of Cypripedium, especially section Cypripedium. It belongs to subgenus Brachypetalum, the most primitive group of Paphiopedilum, but differs from its allied species in hgniva elliptic-lanceolate sepal with cuspidately acuminate apex, rather narrow petals and horizontal lip, which are of common occurrence in many cypripediums, but very rare in paphiopedilums. Apparently, this is an intermediate form, or a link, between Paphiopedilum and Cypripedium, but it does not seem to arise from hybridization between them, because no Cypripedium has been found wherever Paphiopedilum occurs. The new species is distributed in southeastern Yunnan of China. In this area, as well as in river valleys of western Yunnan or the Hengduan Mountains, there have been four species of the same genus reported before. As we know, the Hengduan Mountains and their adjacent areas are rich in Cypripedium. The differentiation of the genus there is remarkable. All five sections it contains occur there and three of them are quite distinctive. For example, the general appearance of the section Bracleosa is dissimilar to that of any other cypripediums, but closely resembles that of Listera. It appears that the difference between sect. Bracteosa of Cypripedium and sect. Brachypetalum of Paphiopedilum is not necessarily wider than that between sect. Bracteosa and sect. Cypripedium of the same genus. Apparently, it is reasonable to consider Paphiopedilum to be an evolutional branch of Cypripedium extending into tropical area, with its primitive group (subgenus Brachypetalum) still remaining in its northern fringe area. This primitive subgenus has eight species, distributed from western Yunnan to the Malay Peninsula. Five of them, including the intermediate and primitive form published here, are found in the hilly land of southeastern Yunnan and the river valleys of western Yunnan. All these facts suggest its area of origin: the river valleys of the Hengduan Mountains and the lower hilly land contiguous to the southof them.

Key words: Orchidaceae, Cypripediloideae, Cypripedium, Paphiopedilum, Subgen.Brachypetalum, Paphiopedilum malipoense, origin, Distribution