1	"Spikelets solitary, not associated with a naked pedicel or rudimentary spikelets"	2
1	"Spikelets paired, if only 1 spikelet functional, a naked pedicel or rudimentary, non-functional spikelet present"	12
2	"Panicles with 1-70 branches, if more than 1, the branches racemosely arranged"	3
2	"Panicles usually composed of a terminal pair of branches, sometimes with 1(-5) additional branches below the terminal pair"	7
3	"Branches 7-70, disarticulating at maturity, the axes extending beyond the distal spikelets"	"Paspalum repens"
3	"Branches 1-6, persistent, terminating in a spikelet"	4
4	"Upper florets olive to dark brown"	"Paspalum scrobiculatum"
4	"Upper florets pale to stramineous"	5
5	"Axes of panicle branches 0.6-1.3 mm wide"	"Paspalum laeve"
5	"Axes of panicle branches 1.8-3.3 mm wide"	6
6	"Spikelets 1.7-2.1 mm long; upper lemmas glabrous throughout"	"Paspalum dissectum"
6	"Spikelets 3.2-4 mm long; upper lemmas with a few short hairs at the apices"	"Paspalum acuminatum"
7	"Upper glumes pilose on the margins or shortly pubescent on the back"	8
7	"Upper glumes glabrous"	9
8	"Spikelets 1.3-1.9 mm long; upper glumes pilose along the margins"	"Paspalum conjugatum"
8	"Spikelets 2.4-3.2 mm long; upper glumes sparsely short pubescent on the back"	"Paspalum distichum"
9	"Spikelets elliptic, their apices acute to acuminate"	10
9	"Spikelets ovate to broadly elliptic, their apices obtuse to broadly acute"	11
10	"Plants rhizomatous, not appearing cespitose; usually in brackish to salt marsh habitats"	"Paspalum vaginatum"
10	"Plants shortly rhizomatous but appearing cespitose; usually in disturbed inland habitats"	"Paspalum almum"
11	"Spikelets 2.5-4 mm long; leaf blades flat or conduplicate"	"Paspalum notatum"
11	"Spikelets 1.9-2.3 mm long; leaf blades flat"	"Paspalum minus"
12	"Spikelets 1-1.3 mm long"	13
12	"Spikelets 1.3-4.1 mm long"	14
13	"Panicle branches 2-6; spikelets elliptic to elliptic-obovate, appressed to the branch axes"	"Paspalum blodgettii"
13	"Panicle branches 18-50; spikelets ovate, diverging from the branch axes"	"Paspalum paniculatum"
14	"Margins of upper glumes and lower lemmas ciliate-lacerate and winged or pilose"	15
14	"Margins of upper glumes and lower lemmas neither ciliate-lacerate nor winged, glabrous or pubescent, if pubescent then the hairs not pilose, often glandular, papillose-based, or wrinkled"	17
15	"Upper glumes and lower lemmas ciliate-lacerate, winged"	"Paspalum fimbriatum"
15	"Upper glumes and lower lemmas pilose"	16
16	"Panicle branches 2-7; spikelets 2.3-4 mm long"	"Paspalum dilatatum"
16	"Panicle branches (4)10-30; spikelets 1.8-2.8 mm long"	"Paspalum urvillei"
17	"Upper florets olive to dark brown"	18
17	"Upper florets white, stramineous, or golden brown"	28
18	"Plants aquatic, the culms decumbent, rooting at the nodes; lower glumes often present"	"Paspalum modestum"
18	"Plants not aquatic or, if aquatic, the culms erect; lower glumes absent"	19
19	"Panicle branches 10-28 or more"	20
19	"Panicle branches 1-10(28)"	22
20	"Plants annual; axes of panicle branches broadly winged, wings about as wide as the central portion"	"Paspalum boscianum"
20	"Plant perennial; axes of panicle branches narrowly winged, wings narrower than the central portion"	21
21	"Axes of panicle branches 1-1.7 mm wide; spikelets 1.8-2.4 mm wide"	"Paspalum virgatum"
21	"Axes of panicle branches 0.5-1.2 mm wide; spikelets 1.1-1.8 mm wide"	"Paspalum conspersum"
22	"Plants annual"	23
22	"Plants perennial"	24
23	"Spikelets 1.3-1.8 mm wide, broadly elliptical to orbicular, glabrous; panicles with 1-10(28) branches, the axes 0.7-2.3 mm wide"	"Paspalum boscianum"
23	"Spikelets 1.7-2.4 mm wide, broadly obovate, shortly pubescent; panicles with 1-5 branches, the axes 0.8-1.3 mm wide"	"Paspalum convexum"
24	"Plants cespitose, rhizomes sometimes present but not well-developed; culms 100-200 cm tall, stout; panicle branches ascending, divaricate, or reflexed"	25
24	"Plants not cespitose, rhizomatous; culms 10-150 cm tall, varying in thickness; panicle branches ascending"	26
25	"Leaf blades 7-18 mm wide"	"Paspalum conspersum"
25	"Leaf blades 2.5-4 mm wide"	"Paspalum plicatulum"
26	"Rhizomes short, indistinct"	"Paspalum plicatulum"
26	"Rhizomes long, evident"	27
27	"Plants aquatic; upper florets chestnut brown"	"Paspalum wrightii"
27	"Plants not aquatic; upper florets dark brown"	"Paspalum nicorae"
28	"Lower lemmas with well-developed ribs over the veins; upper glumes absent"	"Paspalum malacophyllum"
28	"Lower lemmas not ribbed over the veins; upper glumes present"	29
29	"Panicles with 15-100 branches"	30
29	"Panicles with 1-15 branches"	33
30	"Plants annual; upper glumes and lower lemmas rugose"	"Paspalum racemosum"
30	"Plants perennial; upper glumes and lower lemmas smooth"	31
31	"Plants rhizomatous, not cespitose; branch axes 0.9-1.2 mm wide; panicle branches often arcuate"	"Paspalum intermedium"
31	"Plants cespitose, not rhizomatous; branch axes 0.3-0.6 mm wide; panicle branches straight"	32
32	"Panicle branches spreading to reflexed (rarely ascending); leaf blades 10-23 mm wide; axes of panicle branches 0.3-0.4 mm wide"	"Paspalum coryphaeum"
32	"Panicle branches erect to ascending; leaf blades 4.9-6.1 mm wide; axes of panicle branches 0.5-0.6 mm wide"	"Paspalum quadrifarium"
33	"Spikelet pairs not imbricate; lower glumes usually present"	"Paspalum bifidum"
33	"Spikelet pairs imbricate; lower glumes absent or present"	34
34	"Spikelets 1.3-2.5 mm long"	35
34	"Spikelets 2.5-4.1 mm long"	46
35	"Upper glumes, usually also the lower lemmas, shortly pubescent"	36
35	"Upper glumes and lower lemmas glabrous"	40
36	"Lower glumes present"	"Paspalum langei"
36	"Lower glumes absent"	37
37	"Panicles both terminal and axillary, the axillary panicles partially or completely enclosed by the subtending leaf sheath"	"Paspalum setaceum"
37	"Panicles all terminal"	38
38	"Leaf blades involute; culms 80-110 cm tall"	"Paspalum laxum"
38	"Leaf blades flat; culms 20-75 cm tall"	39
39	"Spikelets 1.3-2 mm long, 0.7-1 mm wide, elliptic; upper glumes and lower lemmas 5-veined; culm bases swollen"	"Paspalum caespitosum"
39	"Spikelets 2-2.5 mm long, 1.4-1.6 mm wide, ovate; upper glumes and lower lemmas 3-veined; culm bases not swollen"	"Paspalum virletii"
40	"Panicles both terminal and axillary, the axillary panicles partially or completely enclosed by the subtending leaf sheath"	"Paspalum setaceum"
40	"Panicles all terminal"	41
41	"Upper panicle branches erect"	"Paspalum monostachyum"
41	"Upper panicle branches spreading to ascending"	42
42	"Leaf blades mostly involute; plants of sandy or rocky areas, usually on the coast"	"Paspalum pleostachyum"
42	"Leaf blades mostly flat; plants of inland areas or, if coastal, then in marshy areas"	43
43	"Upper glumes and lower lemmas 3-veined"	44
43	"Upper glumes and lower lemmas 5-veined"	45
44	"Leaf blades usually conduplicate, 2.2-8.3 mm wide"	"Paspalum praecox"
44	"Leaf blades usually flat, 5-10 mm wide"	"Paspalum virletii"
45	"Axes of panicle branches 0.2-0.5 mm wide; ligules 0.2-0.4 mm long"	"Paspalum caespitosum"
45	"Axes of panicle branches 1.5-2 mm wide; ligules 2.2-4.7 mm long"	"Paspalum lividum"
46	"Upper glumes, and usually lower lemmas, pubescent"	47
46	"Upper glumes, and usually lower lemmas, glabrous"	49
47	"Lower glumes present"	"Paspalum langei"
47	"Lower glumes absent"	48
48	"Leaf blades 2-5 mm wide; upper glumes and lower lemmas abundantly pubescent, most hairs longer than 0.1 mm; spikelets elliptic"	"Paspalum hartwegianum"
48	"Leaf blades 4-18 mm wide; upper glumes and lower lemmas glabrous or sparsely pubescent, the hairs shorter than 0.1 mm; spikelets obovate to elliptic"	"Paspalum pubiflorum"
49	"Upper florets golden brown"	50
49	"Upper florets stramineous to pale, but not golden brown"	52
50	"Plants not rhizomatous; culms decumbent and rooting at the lower nodes; spikelets 1.3-1.6 mm wide; lower lemmas 5-7-veined; lower glumes often present"	"Paspalum modestum"
50	"Plants rhizomatous; culms erect, not rooting at the lower nodes; spikelets 1.9-3.1 mm wide; lower lemmas 3-veined"	51
51	"Panicle branches 1-6; upper glumes 5-veined; leaf blades 3-18 mm wide"	"Paspalum floridanum"
51	"Panicle branches 1-3; upper glumes 3-veined; leaf blades 3-4 mm wide"	"Paspalum unispicatum"
52	"Terminal panicle branches erect"	53
52	"Terminal panicle branches spreading to ascending"	54
53	"Blades involute; upper glumes 1-veined"	"Paspalum monostachyum"
53	"Blades flat; upper glumes 3-veined"	"Paspalum unispicatum"
54	"Spikelets 2.2-2.6 mm long"	55
54	"Spikelets 2.6-4.1 mm long"	56
55	"Spikelets 1.2-1.5 mm wide, elliptic to obovate"	"Paspalum lividum"
55	"Spikelets 2-2.8 mm wide, orbicular to suborbicular"	"Paspalum praecox"
56	"Plants decumbent, rooting at the lower nodes, not rhizomatous; spikelets obovate to elliptic"	"Paspalum pubiflorum"
56	"Plants rhizomatous, neither decumbent nor rooting at the lower nodes; spikelets orbicular to elliptic"	57
57	"Spikelets 2.1-3.1 mm long, 2-2.8 mm wide, orbicular to suborbicular; upper glumes 3-veined; leaf blades conduplicate"	"Paspalum praecox"
57	"Spikelets 2.9-4.1 mm long, 1.9-3.1 mm wide, suborbicular to elliptic; upper glumes 5-veined; leaf blades flat"	"Paspalum floridanum"