Flora of North America species comparison

5-160 cm, erect, not rooting at the lower nodes;

nodes glabrous.

65-400 cm, erect;

nodes pilose.

densely pubescent, occasionally glabrous;

ligules 1-2.2 mm;

blades to 55 cm long, 2.2-8.3 mm wide, conduplicate (occasionally flat), glabrous below, pubescent above.

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 2-10 racemosely arranged branches;

branches 0.8-10.3 cm, divergent to spreading, often arcuate, terminating in a spikelet;

branch axes 0.8-2 mm wide, narrowly winged, glabrous, margins scabrous.

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.

2.1-3.1 mm long, 2-2.8 mm wide, paired, imbricate, appressed to divergent from the branch axes, orbicular to suborbicular, stramineous.

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.

1.9-2.1 mm, brown.

glumes absent;

upper glumes and lower lemmas glabrous, 3-veined, margins entire;

upper florets white to light yellow.

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.

= 20, 40.

= 20, 40, 60.