Flora of North America species comparison

25-90 cm.

25-120 cm, decumbent to erect, sometimes trailing and rooting at the nodes, terete or weakly compressed;

nodes terete or slightly compressed, (0)1-3 exserted.

closed for 1/2 - 3/4 their length, smooth or sparsely scabrous, margins not ciliate;

ligules 0.3-2.1 mm, smooth or sparsely scabrous, truncate to obtuse, ciliolate;

blades 0.6-3.5 mm wide, flat.

closed for about 1/3-1/2 their length, compressed, usually densely scabrous, bases of basal sheaths glabrous, distal sheath lengths 0.5-4 times blade lengths;

collars smooth or scabrous, glabrous;

ligules 3-10 mm, scabrous, acute to acuminate;

blades 1-5 mm wide, flat, lax, soft, sparsely scabrous over the veins, margins scabrous, apices narrowly prow-shaped.

mainly pseudointravaginal.

intra-vaginal.

7.5-15(18) cm, lax, pyramidal, open, sparse;

nodes with 1-3(5) branches;

branches 3-8 cm, ascending, straight to spreading, angled, angles prominent, scabrous.

8-25 cm, erect or lax, pyramidal, open, with 35-100+ spikelets;

nodes with 3-7 branches;

branches 2-8(10) cm, ascending to spreading, flexuous to fairly straight, angled, angles densely scabrous, crowded, with 5-35 spikelets in the distal 1/2-3/4.

4-6.5 mm, laterally compressed;

florets 2-5;

rachilla internodes to 1 mm, smooth, glabrous.

2.3-3.5 mm, lengths to 3 times widths, laterally compressed;

florets 2-4, bisexual;

rachilla internodes smooth or muriculate.

1/2-1/3 the length of the adjacent lemmas, distinctly keeled, keels scabrous;

lower glumes subulate to narrowly lanceolate, (1)3-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed;

lemmas (2.5)3.2-4.7 mm, lanceolate, green, distinctly keeled, keels and marginal veins long-villous, hairs extending up almost the whole keel length, lateral veins prominent, intercostal regions smooth, minutely bumpy, usually glabrous, rarely sparsely softly puberulent, apices acute, blunt, or pointed, white, not bronze;

palea keels softly puberulent at midlength, apices scabrous;

anthers (0.5)0.8-1.2(1.5) mm.

distinctly keeled, keels scabrous;

lower glumes subulate to narrowly lanceolate, usually arched to sickle-shaped, 1-veined, distinctly shorter than the lowest lemmas;

calluses webbed, hairs over 2/3 the lemma length;

lemmas 2.3-3.5 mm, lanceolate, distinctly keeled, keels usually sparsely puberulent to 3/5 their length, marginal veins usually glabrous, infrequently the proximal 1/4 softly puberulent, intercostal regions smooth, glabrous, upper lemmas sometimes glabrous, lateral veins prominent, margins glabrous, apices acute;

palea keels smooth, muriculate, tuberculate, or minutely scabrous;

anthers 1.3-2 mm.

= 28.

= 14.