Flora of North America species comparison

20-90 cm tall, 1.8-2.8 mm thick, erect, rigid, simple or branching from the lower and middle nodes;

nodes glabrous or sparsely hispid;

internodes glabrous.

20-210 cm, stout, not woody;

nodes puberulent;

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

generally shorter than the internodes, not keeled, lower nodes glabrous or hispid, hairs papillose-based, particularly near the summits;

ligules 0.5-1 mm;

blades 3-25 cm long, 2-8 mm wide, often distichous, flat to slightly involute, firm, adaxial surfaces pilose basally, glabrous or sparsely pubescent abaxially.

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.

3-24 cm long, usually less than 5 cm wide, open;

primary branches 2-11 cm, alternate, few, stiffly ascending to spreading;

pedicels 1-6 mm, subappressed.

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.

2.2-2.8 mm long, 0.8-1.3 mm wide, ellipsoid-ovoid, pale green, acute, upper glumes and lower lemmas sometimes separating (gaping) beyond the florets.

4-6 mm, ovoid, usually glabrous.

0.5-1 mm, 1/5 – 2/5 as long as the spikelets, glabrous, faintly 1-5-veined, subtruncate to broadly acute;

upper glumes and lower lemmas glabrous, extending 0.1-0.5 mm beyond the upper florets, scarcely separated;

upper glumes 7-11-veined, shorter than the lower lemmas, acute to short-acuminate;

lower florets staminate;

lower lemmas 7-11-veined;

lower paleas 1.9-2.1 mm, oblong;

upper florets 1.8-2.7 mm long, 0.7-1.3 mm wide, broadly ellipsoid, broadest at or above the middle, glabrous, shiny, smooth, apices rounded.

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.

- 36, 40, 45, 54.

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