Urochloa P.Beauv.
Type species: U. panicoides P.Beauv.
Annuals or perennials. Ligule a membranous shortly ciliate rim. Culm erect or decumbent, simple or sparingly branched. Inflorescence a panicle of racemes along a common rachis; branches appressed or spreading, terminating in a spikelet. Spikelets secund, ± appressed to rachis adaxially or abaxially, terete or dorsiventrally compressed, solitary, paired or clustered, 2-flowered; disarticulation below glumes; lower floret Ø, ♂, sometimes ⚥, upper floret ⚥. Lower glume nerveless, upper ≈ spikelet, 5-nerved. Lower floret: lemma 5-7-nerved, membranous to chartaceous, muticous; palea present or 0. Upper floret: lemma ≈ lemma of lower floret, chartaceous to cartilaginous, dull, rugose, margins incurved and clasping palea, apex muticous to mucronate; palea 2-nerved, similar to lemma in texture; lodicules 2, cuneate, truncate; stamens 3; ovary apex glabrous, styles free to base, stigmas plumose; caryopsis ovoid to ellipsoid, dorsiventrally compressed, embryo ½-¾ length of caryopsis, hilum subbasal, punctiform, elliptic or linear.
Key
c. 120 pantropical spp. Naturalised sp. 1; transient sp. 1.
In recent years most species of the related genus Brachiaria (Trin.) Griseb. have been transferred to Urochloa; see especially Morrone, O. and Zuloaga, F. O. Darwiniana 31: 43-109 (1992) who made an intensive study of generic characteristics and limits and the relationship of Urochloa with other genera of Paniceae.
