Flora of North America species comparison

30-100 cm, erect;

nodes glabrous.

3-800 cm, not woody, sometimes branching above the base;

internodes solid or hollow.

glabrous, margins ciliate;

ligules 0.2-0.5 mm, membranous, ciliate;

blades (10)30-60 cm long, 2-8(12) mm wide, flat to folded, glabrous, margins ciliate basally.

all terminal, 6-20 cm long, 20-53 mm wide, fully exerted from the sheaths, erect, green to brown, deep purple, or stramineous to creamy-white;

rachises terete, with pubescent hairs.

spicate panicles with highly reduced branches termed fascicles;

panicles 1-many per plant, terminal on the culms or on both the culms and the secondary branches, or terminal and axillary, or only axillary, usually completely exposed at maturity;

rachises usually terete, with (1)5-many fascicles;

fascicle axes 0.2-7.5(28) mm, with (1)3-130+ bristles and 1-12 spikelets.

5.5-8.4 mm, sessile or subsessile, glabrous;

pedicels to 0.1 mm;

lower glumes 0.2-1.4 mm, veinless;

upper glumes 2-4.9 mm, to 1/2 as long as the spikelet, 1-5-veined, acute to broadly acute;

lower florets sterile;

lower lemmas 4.9-8.1 mm, 7-9(10)-veined;

lower paleas absent;

upper lemmas 5.2-7.6 mm, 5-7-veined, acuminate;

anthers 3, 3-4.5 mm.

with 2 florets;

lower glumes absent or present, 0-5-veined;

upper glumes longer, 0-11-veined;

lower florets sterile or staminate;

lower lemmas usually as long as the spikelets, membranous, 3-15-veined, margins usually glabrous;

lower paleas present or absent;

upper lemmas membranous to coriaceous, 5-12-veined;

upper paleas shorter than the lemmas but similar in texture;

lodicules 0 or 2, glabrous;

anthers 3, if present, x = 5,7, 8,9 (usually 9).

9-16 per cm;

fascicle axes 1.5-5.6 mm, with a stipelike base of 1-5.6 mm and 1(2) spikelet(s);

outer bristles 13-19, 0.8-15.6 mm;

inner bristles 7-10, 11.2-30 mm, scabrous;

primary bristles 26.7-35 mm, scabrous, usually not noticeably longer than the other bristles.

membranous and ciliate, or of hairs, rarely completely membranous;

blades sometimes pseudopetiolate.

free or fused at the base, disarticulating with the spikelets at maturity; of 3 kinds, outer, inner, and primary, in some species with all 3 kinds present below each spikelet, in others 1 or more kinds missing from some or all of the spikelets;

outer (lower) bristles antrorsely scabrous, terete;

inner (upper) bristles antrorsely scabrous or long-ciliate, usually flatter and wider than the outer bristles;

primary (terminal) bristles located immediately below the spikelets, solitary, antrorsely scabrous or long-ciliate, often longer than the other bristles associated with the spikelet;

disarticulation usually at the base of the fascicles, sometimes also beneath the upper florets.

= 18.