1	"At least the lowermost panicle branches whorled; panicles open or loosely contracted"	2
1	"Panicle branches not horled, not even the lowermost"	6
2	"Plants perennial"	"Sporobolus iocladus"
2	"Plants annual"	3
3	"Grains spherical or subglobose"	4
3	"Grains obovate"	5
4	"Grains 0.85-1 (-1.5) mm in diameter; spikelets 2-2.7 mm long"	"Sporobolus panicoides"
4	"Grains about 0.3 mm in diameter; spikelets about 0.7 mm long"	"Sporobolus minimus"
5	"Leaves 0.5-0.8(-1.3) mm wide"	"Sporobolus minutus"
5	"Leaves 3-7 mm wide"	"Sporobolus coromandelianus"
6	"Panicles dense, spikelike or the primary branches bearing spikelets or branchlets from the base"	7
6	"Panicles loose and diffuse or, if spikelets clustered, the primary branches without spikelets or branchles for at least the lower 1/4 of their length"	13
7	"Leaves pungent, often tightly rolled; panicles spikelike or, if plants forming dense cushions up to 10 cm deep and with short, broad, flat leaves, see Sporobolus letourneuxii)"	8
7	"Leaves not pungent"	9
8	"Panicles smoothly cylindrical; leaves not conspicuously distichous"	"Sporobolus spicatus"
8	"Panicles untidily cylindrical; leaves conspicuously distichous"	"Sporobolus virginicus"
9	"Lower glume as long as the spikelet or almost so, 1-veined; upper glume similar"	10
9	"Lower glume up to 1/2 as long as the spikelet, hyaline, without a vein; upper glume about 3/4 the length of the lower glume"	11
10	"Stems 3.5-8 mm in diameter at the base; glumes acute"	"Sporobolus consimilis"
10	"Stems about 1 mm in diameter at the base; glumes acuminate"	"Sporobolus helvolus"
11	"Basal sheaths becoming fibrous with age"	"Sporobolus pellucidus"
11	"Basal sheaths becoming broad and papery with age"	12
12	"Panicles dense, the primary branches appressed"	"Sporobolus brockmanii"
12	"Panicles open, the primary branches spreading or ascending"	"Sporobolus fimbriatus"
13	"Spikelets clustered about the branches or branchlets"	14
13	"Spikelets evenly distributed, not clustered, the panicle diffuse"	20
14	"Spikelets appressed or secund along much of the branches or branchlets"	15
14	"Spikelets gathered into clumps at the tips of the branches or branchlets"	17
15	"Basal sheaths becoming fibrous with age"	"Sporobolus angustifolus"
15	"Basal sheaths not becoming fibrous with age"	16
16	"Stems 1-2 m tall, 3-4 mm in diameter at the base"	"Sporobolus macranthelus"
16	"Stems up to 1 m tall, 1-3 mm in diameter at the base"	"Sporobolus agrostoides"
17	"Panicles more or less contracted, the primary branches short and stiff"	18
17	"Panicle branches loose and open, the branches and branchletts slender, flexuous"	19
18	"Plants densely tufted, forming cushions up to 10 cm deep; leaves short, broad, and densely imbricate"	"Sporobolus tourneuxii"
18	"Plants loosely tufted with extensively creeping stolons; leaves slender, not at all imbricate"	"Sporobolus ruspolianus"
19	"Basal sheaths becoming indurated and often invested with fibres; plants densely tufted from a short, oblique rhizome"	"Sporobolus nervosus"
19	"Basal sheaths neither indurated nor fibrous; plants with slender creeping rhizomes and weak, often geniculate, stems"	"Sporobolus confinus"
20	"Leaves pungent"	21
20	"Leaves not pungent"	22
21	"Lower glume broadly ovate, embracing the base of the remain portion of the spikelet and not more than 1/4 its length; spielets 1.2-2 mm long"	"Sporobolus compactus"
21	"Lower glumes oblong, narrower than the spikelets and at least 1/2 its length; spikelets 1.7-2.3(-2.8) mm long"	"Sporobolus somalensis"
22	"Plants delicate annuals"	"Sporobolus tenuissimus"
22	"Plants tufted perennials"	23
23	"Basal sheaths at most shortly ciliate on the margins, eventually disintegrating into thin, brown fibres, these not woolly tomentose within"	"Sporobolus festivus"
23	"Basal sheaths woolly tomentose with curly hairs on the marings, eventually disintegrating into coarse, yellow fibres, the woolly hairs retained within"	"Sporobolus airiformis"