Description: Terrestrial [or rarely epiphytic or epilithic] herbs, sympodial; roots subterranean, somewhat fleshy. Stems differentiated into rhizome and pseudobulb [or almost undifferentiated]; pseudobulb of several to many internodes.
Leaves scattered along the pseudobulb [or stem, or tufted at its tip, several [or 1–many] per shoot, usually distichous, mostly plicate, petiolate.
Inflorescence racemose, several–many-flowered, lateral; flowers resupinate. Sepals free, similar. Lateral petals free, about as long as, or slightly shorter than sepals. Labellum basally fused along its margins to almost the full length of the column wings to form a tube; lamina deeply 4-lobed [or unlobed to 3-lobed, with a prominent, backward-pointing spur [or spur absent, bearing calli and/or longitudinal keels near the base [or unornamented]. Column lacking free filament and style; column wings fused to column and labellum, expansive in upper half. Column foot absent. Anther incumbent, cap-like. Pollinia 8, waxy. Stigma entire [or 2-lobed]. Rostellum prominent, 2-fid, ventral.
Distribution and occurrence: World: c. 150 species, tropical and subtropical regions, greatest diversity in South-East Asia. Australia: 1 species (native).
Text by P. H. Weston
|One species in NSW: Calanthe triplicata|