1	"Upper lemma obtuse to acute, usually muticous; lower glume adaxial to spikelet bearing axis"	2
1	"Upper lemma obtusely rounded at apex and with distinct mucro; lower glume abaxial to spikelet bearing axis"	14
2	"Inflorescence strictly regular and racemose with spikelets in two regular rows; lower racemes never branching"	3
2	"Inflorescence ± open or with spikelets in several untidy rows; lower racemes sometimes branching"	11
3	"Spikelets up to 3 mm long"	4
3	"Spikelets more than 3 mm long"	5
4	"Spikelets sparsely hairy, ± turgid"	"Urochloa ramosa"
4	"Spikelets glabrous, not turgid"	"Urochloa kurzii"
5	"Strong perennials"	6
5	"Annuals or weak perennials"	7
6	"Lower glume 3/4 to as long as spikelet"	"Urochloa humidicola"
6	"Lower glume 1/3-1/2 as long as spikelet"	"Urochloa decumbens"
7	"Lower glume 1/8-1/6 spikelet length"	"Urochloa occidentalis"
7	"Lower glume 1/3-1/2 spikelet length"	8
8	"Spikelets hairy"	9
8	"Spikelets glabrous"	10
9	"Spikelets with a subapical fringe of silky hairs"	"Urochloa holosericea"
9	"Spikelets evenly hairy or if with longer apical hairs these are not arranged in a fringe"	"Urochloa piligera"
10	"Spikelets reddish; leaf margins serrate"	"Urochloa polyphylla"
10	"Spikelets green to yellow"	"Urochloa subquadripara"
11	"Plant with robust ascending culms 2-6 m tall, with stolons"	"Urochloa mutica"
11	"Plant with slender culms 1 m tall, without stolons"	12
12	"Spikelets c. 2 mm long"	"Urochloa reptans"
12	"Spikelets 3-4 mm long"	13
13	"Spikelets glabrous, 2.8-3.5 mm long; rachilla not pronounced between glumes"	"Urochloa praetervisa"
13	"Spikelets hairy, 3.5-4.6 mm long; rachilla pronounced between glumes"	"Urochloa pubigera"
14	"Lower glume c. 1/3 spikelet length"	"Urochloa panicoides var. panicoides"
14	"Lower glume at least 1/2 spikelet length"	"Urochloa mosambicensis"