Polish Botanical Journal 51(1): 57–59, 2006 GENERA ET SPECIES ORCHIDALIUM. 15. MAXILLARIEAE DARIUSZ L. SZLACHETKO, JOANNA MYTNIK-EJSMONT, MARCIN GÓRNIAK & MAGDALENA ŚMISZEK Abstract. A new genus of the subfamily Vandoideae (Orchidaceae) – Christensonella Szlach., Mytnik, Górniak & Śmiszek, gen. nov. – is described. Its taxonomic position is briefl y discussed and 16 new combinations are made. Key words: Orchidaceae, Vandoideae, Maxillarieae, Christensonella, neotropics Dariusz L. Szlachetko, Joanna Mytnik-Ejsmont*, Marcin Górniak & Magdalena Śmiszek, Department of Plant Taxonomy and Nature Conservation, Gdańsk University, Al. Legionów 9, PL-80-441 Gdańsk, Poland, *e-mail:
[email protected] Maxillarieae Pfi tz. is an exclusively neotropical iorchis Rausch., Mersupiaria Hoehne, Maxillaria, tribe characterized by the presence of a short and Mormolyca Fenzl, Pityphyllum Schltr., Scuticaria wide rostellum, which transforms itself almost Lindl. and Trigonidium Lindl. completely into a narrow viscidium and relatively Within the subtribe there occurs a relative uni- broad tegula. The rostellum is usually deeply in- fi cation of the fl ower structure on one hand; on the cised after the removal of the pollinarium. The other hand, a very large variability of vegetative column foot is usually well-developed. Most spe- characters (such as size and plant types, growth cies possess 4 pollinia (occasionally 2). Maxil- patterns, number of leaves, and inflorescence larieae includes 3 subtribes: Bifrenariinae Dressl., types) can be observed. The adaptation to local Eriopsidinae Szlach., Maxilariinae Lindl. habitats could be a basis of such wide morpho- Maxillariinae (Cymbidioid phylad of the ad- logical variability. However the general morpho- vanced Epidendroideae sensu Dressler 1993) is logical similarity of the fl ower structure may be a very rich and diversifi ed group containing tropical caused by convergence, this being an expression and subtropical orchids.