Description from Flora of China
Herbs, epiphytic or lithophytic (rarely terrestrial), robust, monopodial. Stem long, often up to several meters, climbing, sometimes branched, with many nodes and long internodes. Leaves many, distichous, often oblong, flat, thickly leathery, unequally bilobed, with a sheathing base, and blade jointed to sheath. Inflorescence lateral, relatively long, paniculate, occasionally racemose, laxly many flowered. Flowers resupinate, opening widely, predominantly red or orange, sometimes yellow, flat, medium-sized or large. Sepals and petals free; dorsal sepal and petals similar, spreading; lateral sepals usually broader than dorsal sepal and petals, margins subparallel, undulate. Lip attached to column base, immovable, much smaller than petals and sepals, saccate or spurred, 3-lobed; lateral lobes erect, adaxially with 1 callus at base; mid-lobe often ligulate and recurved, small, with lamellate basal calli; spur conic. Column short and stout, without a foot; rostellar projection short; pollinia 4, in 2 pairs, waxy, reniform, slightly unequal in size, each pair with an elastic thread at base, attached by a common linear stipe to a transversely elliptic viscidium.
Reviewer L. Averyanov notes that Renanthera vietnamensis Averyanov & R. Rice (Oasis 2(3): 3. 2002), described from N Vietnam, also occurs in S China. However, the present authors could not substantiate this record because they found no relevant specimens.
About 19 species: E India through China to the Philippines and south to Malaysia, Indonesia, New Guinea, and the Solomon Islands; three species in China.
(Authors: Chen Xinqi (陈心启 Chen Sing-chi); Jeffrey J. Wood)