Bulbophyllum sect. Polyradices, Fischer & Sieder & Cribb & Kiehn, 2007

Fischer, Gunter A., Sieder, Anton, Cribb, Phillip J. & Kiehn, Michael, 2007, Description of two new species and one new section of Bulbophyllum (Orchidaceae) from Madagascar, Adansonia (3) 29 (1), pp. 19-25 : 20

Bulbophyllum sect. Polyradices

G.A.Fischer, Sieder & P.J. Cribb , sect. nov.

Planta pumila ; pseudobulbi caespitosi bilateraliter compressi unifoliati, inflorescentia sessilis uni- vel biflora , floribus glabris, tepala non ciliata .

TYPUS. — Bulbophyllum petrae G.A.Fischer, Sieder & P.J.Cribb.

REMARKS

This monotypic section is morphologically different from all other sections of Bulbophyllum in Madagascar. In habit it is tiny with densely clustered and bilaterally flattened, unifoliate pseudobulbs, the one- or two-flowered inflorescence is sessile, and the sepals, petals and lip have no hairs but the former are finely papillose on the margin and the latter is slightly papillose beneath. It is also noteworthy that the only species of this section lacks spiral vessels in its tissues, a very rare situation in Madagascan Bulbophyllum . Phylogenetically the new species is placed separately on a basal polytomy as sister to all other major Madagascan clades, without any relationship to one of the described sections (Fischer et al. unpubl. data). The combination of these character states makes the species unique; therefore we propose to place that species in a section of its own.