Description from Flora of China
Centrophorum Trinius, nom. rej.; Pollinia Sprengel, nom. rej.; Rhaphis Loureiro, nom. rej.; Vetiveria Bory.
Perennial, tufted or with spreading rhizomes. Leaf blades mostly basal, usually narrow; ligule a short ciliolate rim or line of hairs. Inflorescence a lax terminal panicle; primary branches whorled, filiform, usually unbranched, each bearing a raceme; racemes composed of few to many spikelet pairs, or more usually reduced to a triad of 1 sessile bisexual spikelet flanked by 2 pedicellate male or barren spikelets; rachis internodes and pedicels slender. Sessile spikelet laterally compressed; callus elongate, acute to pungent, usually bearded; lower glume cartilaginous to leathery, often spinulose; upper glume boat-shaped, usually shortly awned; lower floret reduced to an empty hyaline lemma; upper lemma entire or 2-toothed, awned from apex or sinus or infrequently awnless; awn geniculate, glabrous to pubescent. Pedicelled spikelet dorsally compressed, well developed or reduced, male or barren.
Vetiveria has traditionally been separated from Chrysopogon on the basis of its longer racemes composed of a number of spikelet pairs in addition to the terminal triad. However, it has long been known that intermediates exist, and present knowledge of the group shows that separation into two genera is no longer tenable.
Forty-four species:tropical and warm-temperate regions of the Old World, mainly in Asia and Australia, one species in the SE United States (Florida) and Cuba; four species (one introduced) in China.
(Authors: Chen Shouliang (陈守良); Sylvia M. Phillips)