Flora of North America species comparison

(50)100-180 cm, erect;

nodes pubescent.

10-79 cm, erect;

nodes glabrous.

pubescent, margins extending into auricles;

ligules 1-6.3 mm;

blades 15-62 cm long, 4.9-6.1 mm wide, involute to flat, glabrous.

glabrous, sparsely long pubescent distally;

ligules 1-2 mm;

blades 10-19 cm long, 1.4-8 mm wide, flat or conduplicate, glabrous or pubescent, apices involute.

terminal, with 15-44 racemosely arranged branches;

branches 1.2-8.5 cm, straight, erect to ascending, lower branches longer than those above;

branch axes 0.5-0.6 mm wide, narrowly winged, glabrous, margins scabrous, pubescent, terminating in a spikelet.

terminal, usually composed of a digitate pair of branches, a third branch sometimes present below;

branches 1.1-7.9 cm, diverging to erect;

branch axes 0.4-1.4 mm wide, winged, glabrous, margins scabrous, terminating in a spikelet.

2-2.5(3) mm long, 0.9-1.3 mm wide, paired, divergent to spreading from the branch axes, elliptic, brown to stramineous, often purple-tinged.

3-4.5 mm long, 1.1-2 mm wide, solitary, appressed to the branch axes, elliptic-lanceolate, glabrous, light stramineous, apices acute to acuminate.

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

upper glumes shortly pubescent, 3-veined, purple-spotted, margins entire;

lower lemmas glabrous or pubescent, lacking ribs over the veins, 3-veined, margins entire;

upper florets 2.2-2.5 mm, white.

absent (rarely present);

upper glumes and lower lemmas glabrous, 3-veined;

upper florets white.

2.8-3.1 mm, yellow.

= 20, 30, 40.

= 20, 40, 60.