Description from Flora of China
Amphilophis Nash; Gymnandropogon (Nees) Duthie.
Perennial. Leaf blades linear or lanceolate, sometimes aromatic; ligule membranous, margin ciliolate. Inflorescence terminal, usually of digitate, subdigitate, or corymbiform racemes, infrequently paniculate; racemes shortly pedunculate, composed of several spikelet pairs (if paniculate, more than 8 spikelet pairs present), basal homogamous spikelet pairs absent; rachis internodes and pedicels slender with a median translucent stripe between thickened margins. Sessile spikelet dorsally compressed; callus short, obtuse, bearded; lower glume cartilaginous with herbaceous apex, occasionally herbaceous throughout, broadly convex to slightly concave, flanks rounded, back sometimes with 1–3 deep circular pits, apex subacute; upper glume boat-shaped, dorsally keeled; lower floret reduced to an empty hyaline lemma; upper lemma stipitiform, entire, awned from apex; awn geniculate, glabrous. Pedicelled spikelet similar to the sessile or smaller, herbaceous.
The rachis internodes and pedicels of the closely related genera Bothriochloa and Capillipedium are most distinctive, providing an easy diagnostic character for these genera. The central cells, between the thickened margins, are translucent and frequently purple pigmented. Dichanthium also belongs to this group, but has normal, solid internodes and pedicels. Circular, pitted glands on the lower glume are another remarkable feature of some species in this group.
About 30 species:throughout the tropics and subtropics; three species in China.
(Authors: Chen Shouliang (陈守良); Sylvia M. Phillips)