Flora of North America species comparison

8-100 cm tall, about 1 mm thick, erect to decumbent, simple to profusely branched;

nodes sparsely to densely pilose.

50-300 cm tall, 2-4 mm thick, often compressed, erect or ascending, hard, becoming almost woody;

nodes swollen, glabrous or pubescent;

internodes glabrous, glaucous.

not keeled, shorter than or equal to the internodes, glabrous or the lower sheaths at least partially pubescent, hairs papillose-based;

ligules 0.3-1.5 mm;

blades 10-60 cm long, 3-20 mm wide, elongate, flat, abaxial surfaces and margins scabrous, adaxial surfaces occasionally pubescent near the base, with prominent, white midveins, bases rounded to narrowed.

often crowded basally;

sheaths rounded, usually longer than the internodes, hispid, hairs papillose-based, to 5 mm;

ligules 0.5-1.5 mm;

blades 3-30 cm long, 2-12 mm wide, linear, ascending to erect, flat, hirsute to sparsely pilose, greenish or purplish, bases truncate to subcordate and ciliate on the margins, apices acute.

7-27 cm long, 4-24 cm wide, 1/4 - 1/3 as long as the plants, diffuse, usually exserted at anthesis, not breaking at the base of the peduncles to become a tumbleweed;

rachises glabrous or sparsely pilose basally;

primary branches spreading, secondary branches and pedicels confined to the distal 2/3 secondary branches diverging to appressed, with 1-4 spikelets;

pedicels 3-15 mm, spreading to appressed, scabrous or hirsute;

pulvini glabrous or pilose.

10-45 cm, to 1/2 as wide as long, open or somewhat contracted, with many spikelets;

branches 4-12 cm, opposite or alternate, ascending to spreading;

pedicels 0.3-2.5 mm, scabridulous to scabrous, appressed to diverging less than 45° from the branch axes.

1.4-2.4 mm long, 0.5-0.7 mm wide, usually green, glabrous.

2.4-3.4 mm long, 1-1.3 mm wide, ellipsoid-lanceoloid to narrowly ovoid, often purplish, glabrous, acute.

0.5-0.9 mm, usually less than 1/2 as long as the spikelets, 3-4-veined, truncate to acuminate;

upper glumes 1.6-2 mm, 7-veined, veins not prominent;

lower lemmas 1.6-1.9 mm, 7-9-veined, veins not prominent;

lower paleas absent;

lower florets sterile;

upper florets 1.5-1.7 mm long, about 0.4 mm wide, often dark brown, sometimes disarticulating, apices minutely papillose.

1.4-2.2 mm, 1/3 – 1/2 as long as the spikelets, 3-5-veined, obtuse;

upper glumes and lower lemmas subequal, glabrous, 5-9-veined, margins scarious, acute;

lower florets staminate;

upper florets 1.8-2.8 mm long, 0.9-1.1 mm wide, smooth, lustrous, acute.

= 18.

= 18, 36.