A Note on a Tylosema (Leguminosae-Caesalpinioideae) from Southern Africa

Abstract

Work on 'Flora Zambesiaca' and 'Flora of Southern Africa' requires us to make a decision on the identity of Bauhinia bainesii Schinz in M6m. Herb. Boiss. I: 121 (1900). In the protologue Schinz clearly cited his own collection 2061 from South West Africa, a sterile specimen now at Zuirich (Z) and undoubtedly referable to Tylosema esculentum (Burch.) Schreiber. In his discussion, however, he also referred a collection by Baines, now at Kew and known to have come from Rhodesia, to the same species. No doubt this specimen prompted the epithet bainesii, and it might be assumed that this should therefore be taken as the type of the name. The Baines collection is on two sheets, one bearing stems and flowers only and the other stems, leaves and fruit only, and is clearly referable to Tylosema fassoglense (Schweinf.) Torre & Hillcoat. Brenan, in Fl. Trop. E. Afr. Legum.-Caesalp.: 214 (1967), has given B. bainesii as a synonym of' T.fassoglensis', citing both the Baines and Schinz collections as syntypes, whereas almost simultaneously Schreiber in Prodr. Fl. S.W. Afr. 59: 20 (1967) has given it as a synonym of T. esculentum, citing only Schinz 2061 as type material. A descision on typification of the name is now necessary. It could be argued that Schreiber's citation of the Schinz specimen only could be regarded as implicit lectotypification, but it seems likely that this was unintentional and merely a reflection of editorial policy which cites types of synonyms only when they are from the Flora area. For what it is worth as a possible lectotypification, however, Schreiber's account appears to have priority, having been received at Kew on 3 March 1967 while the Fl. Trop. E. Afr. account is dated May of that year. Consideration of the protologue gives further support for typification in this sense, for Schinz stated that he had before him only a sterile specimen, which is clearly his own 2061. The detailed description given is based only on vegetative characters, evidently taken from this specimen. In his second paragraph he referred to the inflorescence, which might be thought to be derived from the Baines collection, but at the same time referred to the habit and underground parts and uses of the plant by the local tribe in South West Africa, and it is clear that these comments were based on his own field observations. None