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.

20-250 cm tall, 3-10 mm thick, erect or decumbent, simple or branched from the lower nodes;

nodes glabrous;

internodes glabrous, glaucous.

shorter or longer than the internodes, not keeled, glabrous;

collars often glaucous and purplish;

ligules 1-5 mm;

blades 7-50 cm long, 2-13 mm wide, erect or ascending, firm, thick, flat basally, more or less involute towards the apices.

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.

10-80 cm long, 2-17 cm wide, contracted, slightly nodding;

primary branches whorled or opposite, strongly ascending to appressed;

pedicels 0.5-15 mm, appressed to slightly divergent.

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

4-7.7 mm long, 1.5-2 mm wide, narrowly ovoid, glabrous, acuminate;

lower florets staminate.

and lower lemmas relatively thick;

lower glumes 2.8-4 mm, 1/2 - 4/5 as long as the spikelets, 3-9-veined, apices of the midveins sometimes scabridulous;

upper glumes and lower lemmas extending 1.5-3 mm beyond the upper florets, apices stiffly gaping;

upper glumes 3.9-7.6 mm, 5-9-veined;

lower lemmas slightly shorter than the upper glumes, 7-9-veined, lower paleas 3-7 mm, oblong-hastate, folded over the anthers;

lower florets staminate;

upper florets 2.4-3.9 mm long, 1-1.8 mm wide, narrowly ovoid to oblong, glabrous, smooth, shiny, lemma margins clasping the paleas only at the base.

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.

= 18.

= 36, 54.