Flora of North America species comparison

40-300 cm tall, 3-5 mm thick, solitary or forming dense clumps, erect or decumbent, usually simple;

nodes glabrous;

internodes hard, glabrous or glaucous, green or purplish.

20-210 cm, stout, not woody;

nodes puberulent;

internodes usually with papillose-based hairs, sometimes nearly glabrous, not succulent.

longer than the lower internodes, shorter than those above, glabrous or pilose, especially on the throat, margins usually ciliate;

ligules 2-6 mm;

blades 10-60 cm long, 2-15 mm wide, flat, erect, ascending or spreading, glabrous or pubescent, adaxial surfaces sometimes densely pubescent, particularly basally, bases rounded to slightly narrowed, margins scabrous.

numerous;

sheaths terete, densely pilose, with papillose-based and caducous hairs;

ligules membranous, ciliate, cilia 1-3 mm;

blades 15-40 cm long, 7-25 mm wide.

10-55 cm long, 4-20 cm wide, exserted, open;

primary branches thin, straight, solitary to whorled or fascicled, ascending to spreading, scabrous, usually rebranching once;

pedicels 0.5-20 mm, appressed to spreading.

6-20 cm long, 4-11 cm wide, included or shortly exserted at maturity, dense;

branches stiff, appressed to spreading, spikelets solitary, confined to the distal portions;

pedicels 1-9 mm, scabrous and sparsely pilose.

2.5-8 mm long, 1.2-2.5 mm wide, narrowly lanceoloid, turgid to slightly laterally compressed, glabrous, acuminate.

4-6 mm, ovoid, usually glabrous.

glumes 1.8-3.2 mm, 1/2 - 4/5 as long as the spikelets, glabrous, 5-9-veined, acuminate;

upper glumes and lower lemmas extending 0.4-3 mm beyond the upper florets, 7-11-veined, strongly gaping at the apices;

lower florets staminate;

lower paleas 3-3.5 mm, ovate-hastate, lateral lobes folded over the anthers before anthesis;

upper florets 2.3-3 mm long, 0.8-1.1 mm wide, narrowly ovoid, smooth, glabrous, shiny;

upper lemmas clasping the paleas only at the base.

glumes 2.8-3.6 mm, 1/2 - 3/4 as long as the spikelets, 5-7-veined, veins scabridulous distally, apices attenuate;

upper glumes 4-5.1 mm, slightly exceeding the upper florets, 11-13(15)-veined, veins scabridulous distally;

lower florets sterile;

lower lemmas 4-4.8 mm, slightly exceeding the upper florets, 9-13-veined, veins scabridulous distally;

lower paleas 1.2-1.6 mm, 1/2 or less the length of the upper florets, truncate to bilobed;

upper florets 3-3.8 mm long, 2-2.5 mm wide, smooth or striate, more or less shiny, stramineous to orange, red-brown, or blackish, persisting in the spikelets or disarticulating at maturity.

= 18, 21, 25, 30, 32, 35, 36, 54-60, 67-72, 74, 77, 90, 108.

= 36, 40, 42, 49, 54, 72.