Part 7 - UNC Herbarium

POACEAE 904
25 Panicles with 1-15 branches.
29 Spikelets 2.5-4.1 mm long.
30 Spikelet pairs barely if at all imbricate; lower glumes usually present ............... P. bifidum
30 Spikelet pairs imbricate; lower glumes absent or present.
31 Upper glumes pubescent; lower lemmas usually pubescent.
32 Lower glumes present......................................................................... [P. langei]
32 Lower glumes absent .....................................................................P. pubiflorum
31 Upper glumes glabrous; lower lemmas usually glabrous.
33 Upper florets golden brown ...........................................................P. floridanum
33 Upper florets pale to tan.
34 Terminal panicle branches erect....................................[P. monostachyum]
34 Terminal panicle branches spreading to ascending.
35 Plants decumbent, rooting at the lower nodes; spikelets obovate to
elliptic ............................................................................P. pubiflorum
35 Plants rhizomatous; spikelets orbicular to elliptic.
36 Spikelets 2.9-4.1 mm long; 1.9-3.1 mm wide, suborbicular to
elliptic; upper glumes 5-veined; leaf blades flat.....P. floridanum
36 Spikelets 2.1-3.1 mm long, 2.0-2.8 mm wide, orbicular or nearly
so; upper glumes 3-veined; leaf blades laterally folded.
37 Lower sheaths villous or hirsute...........................................
................................................ P. praecox var. curtisianum
37 Lower sheaths glabrous or sparsely papillose pubescent......
.......................................................P. praecox var. praecox
29 Spikelets 1.3-2.5 mm long.
38 Upper glumes (and usually also the lower lemmas) shortly pubescent.
39 Lower glumes present................................................................................. [P. langei]
39 Lower glumes absent.
40 Panicles both terminal and axillary, the axillary panicles partially or completely
enclosed by the subtending leaf sheath ................................................................
........................................................... [see Key to Paspalum setaceum complex]
40 Panicles all terminal.................................................................. [P. caespitosum]
38 Upper glumes and lower lemmas glabrous.
41 Panicles both terminal and axillary, the axillary panicles partially or completely
enclosed by the subtending leaf sheath ...... [see Key to Paspalum setaceum complex]
41 Panicles all terminal.
42 Upper panicle branches erect ................................................[P. monostachyum]
42 Upper panicle branches spreading to ascending.
43 Upper glumes and lower lemmas 5-veined .......................... P. caespitosum
43 Upper glumes and lower lemmas 3-veined.
44 Lower sheaths villous or hirsute.............. P. praecox var. curtisianum
44 Lower sheaths glabrous or sparsely papillose pubescent......................
.......................................................................P. praecox var. praecox
Key to Paspalum setaceum complex
(by Richard J. LeBlond)
1 Leaves variously pubescent.
2 Leaves villous to villous-hirsute, 2-10 mm wide; spikelets 1.3-1.9 mm long.
3 Leaves villous, 2-7 mm wide, not especially crowded toward the base, erect to spreading; [widespread] .................
......................................................................................................................................... P. setaceum var. setaceum
3 Leaves villous-hirsute, 3-10 mm wide, crowded toward the base, recurved; [of n. FL south to Cuba].......................
................................................................................................................................[P. setaceum var. villosissimum]
2 Leaves puberulent, pilose, or hirsute, 3-15 mm wide; spikelets 1.6-2.5 mm long.
4 Leaves puberulent at least distally on the adaxial surface (and often also pilose in var. stramineum); spikelets 1.6-
2.2 mm long.
5 Plants erect to spreading; leaves puberulent and often pilose to nearly glabrous except for the puberulent
distal adaxial surface; spikelets glabrous to pubescent......................................... P. setaceum var. stramineum
5 Plants spreading to prostrate; leaves densely puberulent; spikelets pubescent....................................................
....................................................................................................................... P. setaceum var. psammophilum
4 Leaves pilose or hirsute but not puberulent; spikelets 1.8-2.5 mm long.
6 Plants mostly erect; leaves pilose; spikelets usually glabrous; sterile lemma midnerve usually present............
...........................................................................................................................P. setaceum var. muhlenbergii