Bauhinia loeseneriana Reinstated, with Notes on the Forests of the Rondo Plateau, Se Tanzania

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Bauhinia loeseneriana Harms (1902, p. 158) was described from a single collection (Busse 1027) from Tanzania, Mtwara Region, Rovuma Valley, Kwa Mkopo. This locality is not mentioned by Busse (1902) but must, judged by the collecting date and his itinerary (Busse 1902, p. 97), be located somewhere along the north side of the Rovuma River not more than 50 km inland from the coast. In the original publication Harms mentioned that the flowers are in a bad state, and that a detailed description is therefore impossible. He also stated that according to Busse the flowers are yellow. Brenan (1967, p. 210) united Bauhinia loeseneriana with B. mombassae Vatke, a yellow-flowered species known only from around Mombassa in Kenya. Brenan pointed out that the type of B. loeseneriana differs from B. mombassae in the truncate or rounded leaf-base (cordate in B. mombassae), and 5-6 mm long "points" to the sepals (obtuse in B. mombassae). Brenan regarded these differences as being "of little taxonomic importance" and he consequently considered B. loeseneriana to be "only a minor variation of B. mombassae". During a recent expedition to the Rondo Plateau in SE Tanzania the authors made two collections (Bidgood, Abdallah & Vollesen 1385 and 1666) of a beautiful Bauhinia with pure white flowers. They represent a species very different from the only other white-flowered species in East Africa (B. taitensis), and they clearly do not key out to any of the species recognised by Brenan (1967). Examination of a photo at Kew of the duplicate of Busse 1027 at Nairobi (EA), and of Paulo 216 (K), a collection from Morogoro Region, Nguru Mts. mentioned by Brenan (1967, p. 210) as matching the type, has convinced us that what we collected is Bauhinia loeseneriana. It is equally evident that this is a distinct species which morphologically is quite different from and probably not very closely related to B. mombassae. We consider it most likely that Brenan (1967, p. 210) was misled by Harms' statement (based on Busse's field notes) about the corolla of B. loeseneriana being yellow. In this connection it is worth mentioning again Harms' comment about the poor state of the flowers, and it is, in our opinion, quite possible that Busse only saw old faded flowers. In all other respects our material is a perfect match to Busse 1027 and to Paulo 216.