Polish Botanical Journal 53(2): 97–101, 2008 FOUR NEW SPECIES OF BILABRELLA (ORCHIDACEAE, HABENARIINAE) FROM AFRICA MARTA KRAS & DARIUSZ L. SZLACHETKO Abstract. Four new species of the genus Bilabrella Lindl. (Orchidaceae, Habenariinae) from Africa are described and illustrated, and their taxonomy is briefly discussed. Key words: Orchidaceae, Habenaria, Bilabrella, new species, systematic Marta Kras & Dariusz L. Szlachetko, Departament of Plant Taxonomy and Nature Conservation, Gdańsk University, PL-80-441 Gdańsk, Al. Legionów 9, Poland, e-mail: bgmk@univ.gda.pl The genus Bilabrella was described in 1834 by John Lindley. Bilabrella falcicornis Lindl. was the only species classified within the genus. The diag- nostic features provided by Lindley in his diagnosis were as follows: fleshy sepals, medium-sized lateral sepals, leathery and relatively large petals, fleshy trilobed lip, anther furnished with antherophores which are free and turned upward, linear-lanceolate, curved and elongate rostellum, fleshy rostellophores bent upwards, leafy stem, linear and leathery leaves and elongate inflorescence. Unfortunately, none of these features could be used to distinguish Bilabrella; because of that, Lindley sunk Bilabrella into Habenaria a few years later (Lindley 1840). Nothing changed in the classification of the genus until, on the basis on their detailed revision of herbarium material and literature data, we decided not to recognize sec- tions Bilabrellae Kraenzl. and Replicatae Kraenzl; at the same time we reinstated Bilabrella and transferred 60 species to the genus (Szlachetko & Kras-Lapinska 2003). After further studies we changed the taxonomic status of 11 more species (Szlachetko & Kras 2006). The genus Bilabrella is distinguishable from other representatives of Habe- nariinae by the specific combination of several features. The most important diagnostic characters are these: strongly asymmetric and upward-turned lateral sepals furnished with a lateral apiculus, bi- partite petals split almost up to the base, deeply trilobed lip with filiform or linear lobes; and gynostemium strongly elongate, almost filiform rostello-, anthero- and stigmaphores, distinctive auricles and relatively short and oval anther. As a consequence of further detailed studies based on new collections, we transferred more taxa to Bilabrella, so that presently 88 species are included in the genus. To these, we propose four species as new to science. Bilabrella kraenzliniana Kras & Szlach., sp. nov. Fig. 1 Haec nova species omnibus generis speciebus labelli forma differt: medius lobus in basalem partem obovatus est. Bilabrella welwitschii (Rchb.f.) Szlach. & Kras-Lap. similis est sed petalorum loborum forma et gynostemii structura differt. Bilabrella cribbiana (Szlach. & Olsz.) Szlach. & Kras-Lap. similis est sed petalibus differt. TYPE: KENYA. SITOTAN, near Lumbwa, alt. 2550 m, Nov. 1936, Graham 3736B (HOLOTYPE – BR!). ETYMOLOGY. Dedicated to Friedrich (Fritz) Wilhelm Ludwig Kraenzlin (1847–1934), the au- thor of the only published revision of the genus Habenaria. Plant 36 cm tall, rather erect. Leaves 8.5 × 0.7 cm, linear, acute, spread, the upper ones sheathlike, sparsely hairy on both surfaces. In- florescence 6 cm long, 12-flowered, lax. Floral