Physoceras Schltr., Repert. Spec. Nov. Regni Veg. Beih. 33: 78 (1924).
Plants terrestrial or epiphytic, with several tubers stem with its bane surrounded by brown or black sheaths, totally without a limbus, bearing a single sessile leaf without sheaths, persisting with the flowerless scapes for 1-2 years, after flowering. Inflorescence racemiform loosely several flowered (2-10 flowered). Petals adnate to the median sepal, forming a helmet over the anther. Labellum trilobed, median lobe more or less bilobed, apically. Anther with a deep channel and bilobed apically, the two lobules forming a bursicule, in which the viscidiums are housed, Other characteristics are as those of Cynorkis.
W. Indian Ocean

Physoceras australe Boiteau Madagascar.
Physoceras bellum Schltr. N. Madagascar.
Physoceras betsomangense Bosser N. Madagascar.
Physoceras bifurcum H.Perrier Madagascar.
Physoceras boryanum (A.Rich.) Bosser Mascarenes.
Physoceras epiphyticum Schltr. N. Madagascar.
Physoceras lageniferum H.Perrier Madagascar.
Physoceras mesophyllum (Schltr.) Schltr. N. Madagascar.
Physoceras perrieri Schltr. N. Madagascar.
Physoceras rotundifolium H.Perrier N. Madagascar.
Physoceras violaceum Schltr. N. & NE. Madagascar.

World Checklist of Monocotyledons. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; accessed1/20/2010
Bibliography and References:
Flora of Madagascar Perrier 1939/1981
Orchids of Madagascar Hermans 2007
Field Guide to the Orchids of Madagascar Cribb & Herman 2009