Tylostigma nigrescens Schltr., Beih. Bot. Centralbl. 34(2): 298 (1916).
Herbs to 60 cm. tall, blackish when dried; tubers fasciculate, narrowly napiform; stern sheathed basally with several narrowly appressed sheaths, bearing 1-2 leaves medially, and several sheaths with a narrowly acuminate limbus above, leaves narrowly linear (nearly 23 cm. x 2-3 mm.). Rachis densely many flowered, to nearly 13 cm, long; bracts lanceolate-acuminate, slightly longer than the flower; flowers white. Sepals oblong-obtuse, generally 2 mm. long, with the laterals oblique and carinate. Petals oblong, very obtuse, 2 veined, slightly longer than the median sepal. Labellum 2 mm. long, cordate basally, widely oval, obtuse, provided above the base with a transverse, slightly arched lamella. Column 1,5 mm tall. Ovary generally 4 mm long.
Marshes in large groves of Cypress, between 1500 and 2000m. alt.;
C. Madagascar
Flora of Madagascar: vascular plants: 49th family, Orchids / by H. Perrier de La Bathie; published under the auspices of the government of Madagascar and under the direction of H. Humbert; English revision and translation by Steven D. Beckman; Field Guide to the Orchids of Madagascar Cribb & Hermans 2009
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Habitat/In situ 
tylostigma nigrescens 
Photograph ©Gilles
Grunenwald. Image used
with kind permission.