Aerial stem-parasitic shrubs (haustorial structure unknown). Leaves opposite. Inflorescencess axillary, a sessile involucrate head of 12-18 sessile flowers arranged mostly in triads on a short receptacle; involucral bracts decussate, each subtending a triad, imbricate, enclosing the developing flowers; bracts of the individual flowers usually 3, foliaceous and together enclosing the flower bud. Fruit not known.
Asia-Tropical: Philippines (Philippines present)
Endemic to Malesia; one species known only from the Philippines.
The triads of flowers in the inflorescence are apparently not the simple dichasia which occur in other genera. Each individual flower is subtended by three bracts, as in Macrosolen, and may therefore represent a reduced true dichasium. The whole inflorescence, with its foliaceous involucral bracts subtending the false triads, may therefore be a condensed complex branching system.
Since the true units of the inflorescence are single flowers with three bracts, and not simple triads, the relationship of Thaumasianthes is probably with Lepidaria rather than with Lepeostegeres. However, its unique inflorescence structure confirms Danser's recognition of Thaumasianthes as a distinct and isolated genus.