Tribonanthes longipetala Lindl.

Scape 6.5-32 cm tall. Inflorescence a solitary flower or a 2-4-flowered cyme; solitary flower subtended sometimes distantly by a leaf-like bract; cymes openly branched, branches with or without associated leaf-like bracts, the longest single flower-bearing (i.e. ultimate) branch usually 11-60 mm long from axil to base of flower. Flowers not fragrant. Perianth lobes ±linear or narrowly obovate, spreading, usually 8.5-14 mm long, 1.6-3.5 mm wide, length : maximum width ratio usually 3.1-6.9, often purple-tinged, especially on midline of abaxial surface; both surfaces uniformly woolly or felted. Filament appendage usually slightly to much shorter than anther tip.

Grows in seasonally wet soils, either swamps or shallow soils over or near granite rock.