Flora of North America species comparison

50-220 cm, erect;

nodes glabrous or pubescent.

65-400 cm, erect;

nodes pilose.

glabrous or pubescent;

ligules 1-4(7.7) mm;

blades 12-60 cm long, 2-12 mm wide, flat, mostly glabrous, a few long hairs near the base of the adaxial surface.

papillose-hirsute (upper sheaths sometimes glabrous);

ligules 1-4.5 mm;

blades 30-50 cm long, 10-23 mm wide, flat, with long hairs behind the ligules, otherwise glabrous or puberulent adaxially.

terminal, with (4)10-30 racemosely arranged branches;

branches 1.2-11.5 cm, divergent;

branch axes 0.5-1.1 mm wide, winged, glabrous, margins scabrous, terminating in a spikelet.

terminal, with (6)15-44 racemosely arranged branches;

branches 5-13 cm, straight, spreading to reflexed, rarely merely divergent;

branch axes 0.3-0.4 mm wide, narrowly winged, glabrous, margins scabrous, pubescent, terminating in a spikelet.

1.8-2.8 mm long, 1.1-1.5 mm wide, paired, appressed to the branch axes, elliptic to slightly obovate, stramineous (rarely purple).

2-2.5 mm long, 1.8-1.9 mm wide, paired, divergent to spreading from the branch axes, elliptic, brown to stramineous, often purple-tinged.

1.2-1.7 mm, white.

glumes absent;

upper glumes and lower lemmas 3-veined, margins pilose;

upper florets stramineous.

glumes usually absent, if present, to 0.9 mm, triangular;

upper glumes smooth, papillose-hirsute, 3-veined;

lower lemmas smooth, papillose-hirsute or glabrous, 3-veined;

upper florets white.

= 40.

= 20, 40, 60.