Aristida L.
Type species: A. adscensionis L.
Annual or perennial tufts, usually with wiry culms and leaves either basal or mostly cauline. Ligule shortly ciliate. Leaf-blade narrow, linear, flat or rolled. Panicle contracted or open, sometimes spike-like. Spikelets 1-flowered, ⚥, narrow, pedicelled; disarticulating above glumes. Glumes equal or unequal, usually 1-nerved, keeled, ± mucronate to shortly awned. Lemma 3-nerved, ± coriaceous, narrow, convolute or involute, terminating in a 3-fid awn, with or without a column. Palea « lemma, 2-nerved. Callus sharp, shortly bearded. Stamens 3, or 1. Lodicules 2 or 3. Caryopsis terete, or grooved; embryo small; hilum linear, almost = caryopsis. Fig. 18.
c. 250 spp., of tropics and subtropics in dry places or in regions of low fertility. Naturalised sp. 1; transient sp. 1.
Esen, A. and Hilu, K. W. Taxon 40: 5-17 (1991), suggested an isolated position for Aristida outside the Arundinoideae; as also do Soreng, R. J. and Davis, J. I. Bot. Rev. 64: 1-85 (1998); currently subfamilial rank is favoured.
