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.

50-140 cm tall, 1.5-2.5 mm thick, usually erect, rarely decumbent, firm;

nodes glabrous or puberulent;

internodes glabrous.

shorter than the internodes, glabrous or hispid, hairs papillose-based, rounded basally;

ligules 0.5-2 mm;

blades 10-30 cm long, 2-8 mm wide, flat, glabrous or sparsely hirsute on 1 or both surfaces.

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.

4-25(40) cm long, 3-14 cm wide, exerted, lax;

primary branches 3-14 cm, opposite and alternate, ascending, glabrous, branching in the distal M;

pedicels 1-4 mm, appressed or spreading.

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

2.5-3.5 mm long, 1-1.2 mm wide, narrowly ovoid to ellipsoid, 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.

1-1.5 mm, about 1/3 as long as the spikelets, glabrous, 1-3-veined, acute;

upper glumes slightly exceeding the lower lemmas, glabrous, acute, scarcely separated from the lower lemmas;

lower florets staminate;

lower lemmas similar to the upper glumes;

lower paleas 2-3 mm, oblong;

upper florets 2-2.5 mm long, 0.8-1 mm wide, ellipsoid, widest below the middle, glabrous, smooth, shiny, apices lightly beaked.

= 18.

= 18, 36, 41, 42, 43, 45, 54, 63 (United States material apparently usually tetraploid, with 2n = 36).