1	"Lower glume more than 1/3 spikelet length"	2
1	"Lower glume 1/8-1/3 spikelet length"	21
2	"Lower floret male"	3
2	"Lower floret sterile"	4
3	"Spikelets 5.5-7 mm long, densely pilose"	"Panicum racemosum"
3	"Spikelets to 3.5 mm long, glabrous"	"Panicum antidotale"
4	"Spikelet 5-6.5 mm long, apex obtuse"	"Panicum miliaceum"
4	"Spikelet less then 5 mm long or if 5 mm long then apex mucronate"	5
5	"Lower glume obtuse to sub-acute"	6
5	"Lower glume acute to acuminate"	8
6	"Lower glume less than half spikelet length"	"Panicum luzonense"
6	"Lower glume at least half spikelet length"	7
7	"Spikelets 0.8-1.4 mm long"	"Panicum trichoides"
7	"Spikelets more than 2 mm long"	"Panicum incomtum"
8	"Lower glume at least 3/4 spikelet length"	9
8	"Lower glume 1/2-2/3 spikelet length"	12
9	"Lower glume ±equal to spikelet length or longer"	10
9	"Lower glume shorter than spikelet"	11
10	"Spikelet 2.5-3 mm long"	"Panicum mindanaense"
10	"Spikelet at least 4 mm long"	"Panicum trachyrhachis"
11	"Annual; inflorescence branches flexuous"	"Panicum seminudum"
11	"Perennial; inflorescence branches divaricately spreading"	"Panicum queenslandicum"
12	"Palea absent in lower floret"	13
12	"Palea present in lower floret"	14
13	"Decumbent and glabrous; rooting at nodes"	"Panicum bisulcatum"
13	"Tufted; leaves with tubercle-based hairs; not rooting at nodes"	"Panicum capillare"
14	"Fertile lemma with a lunate scar at base"	"Panicum hillmanii"
14	"Fertile lemma without a lunate scar at base"	15
15	"Upper glume and lower lemma 9-nerved"	16
15	"Upper glume and lower lemma 5-7-nerved"	17
16	"Tufted perennial; leaves with silky hairs"	"Panicum bombycinum"
16	"Decumbent annual; leaves with tubercle-based hairs"	"Panicum novemnerve"
17	"Culm internodes and base distinctly hairy"	"Panicum effusum"
17	"Culm internodes and base glabrous or slightly hairy"	18
18	"Inflorescence a fairly narrow panicle, with spikelets thinly dispersed in the inflorescence and occupying less than half the height of the culm ; spikelets acute"	19
18	"Inflorescence a large open panicle, with many spikelets occupying at least half the height of the culm; spikelets acuminate"	20
19	"Secondary inflorescence branches poorly developed; sandstone soil"	"Panicum simile"
19	"Secondary inflorescence branches well developed; clay soil"	"Panicum sp. A"
20	"Annual; inhabits limestone outcrops"	"Panicum chillagoanum"
20	"Perennial; habitats other than limestone"	"Panicum mitchellii"
21	"Lower floret male"	22
21	"Lower floret sterile"	24
22	Annual	"Panicum schinzii"
22	Perennials	23
23	"Rhizomatous; lower glume truncate to rounded"	"Panicum repens"
23	"Tufted, with a swollen or knotty base; lower glume acute"	"Panicum coloratum"
24	"Aquatic or swamp grasses"	25
24	"Non-aquatic grasses"	26
25	"Rhizomes thick and spongy; spikelets acuminate"	"Panicum paludosum"
25	"Rhizomes slender; spikelets acute"	"Panicum obseptum"
26	"Prostrate grass with inflorescence up to 7 cm long"	27
26	"Tufted grass with panicles more than 7 cm long"	28
27	"Spikelets less than 2 mm long"	"Panicum pygmaeum"
27	"Spikelets 2-3 mm long"	"Panicum lachnophyllum"
28	"Upper floret somewhat shorter than spikelet"	"Panicum buncei"
28	"Upper floret ±equal to spikelet length"	29
29	"Inflorescence branches ±flexuous, lower ones solitary"	30
29	"Inflorescence branches rigid and spreading, lower ones whorled"	32
30	Perennial	"Panicum  larcomianum"
30	"Annual or biennial"	31
31	"Upper glume 9-11-nerved; glumes with distinct rachilla between them"	"Panicum gilvum"
31	"Upper glume 7-nerved; glumes without distinct rachilla between them"	"Panicum laevinode"
32	"Spikelets 2.5-3.5 mm long"	"Panicum decompositum"
32	"Spikelets 3.5-4.1 mm long"	"Panicum latzii"