Flora of North America species comparison

(5)10-30 cm tall, 1.2-1.5 mm thick, bases decumbent, terete or weakly compressed, hispidulous beneath the panicles;

nodes terete, 0(1) exserted.

(20)30-120 cm, usually stout, erect or decumbent, not branching above the base, terete or weakly compressed;

nodes terete, 1-2 exserted.

closed for about 1/2 their length, terete, smooth or sparsely to moderately retrorsely scabrous near the collars, glabrous, bases of basal sheaths glabrous, distal sheath lengths 0.9-3.5 times blade lengths;

collars sparsely to moderately retrorsely scabrous, glabrous;

ligules 1-2 mm, scabrous, truncate to obtuse, ciliolate;

innovation blades to 30 cm long, adaxial surfaces moderately to densely scabrous or hispidulous on and between the veins;

cauline blades subequal in length, 1-2 mm wide, involute, moderately thick, moderately firm, arcuate, abaxial surfaces smooth or sparsely scabrous, adaxial surfaces moderately to densely scabrous or hispidulous on and between the veins, apices narrowly prow-shaped, flag leaf blades 1-9 cm.

closed for 1/4 - 3/5 their length, terete to compressed, usually distinctly keeled, glabrous, sparsely to moderately scabrous, bases of basal sheaths glabrous, distal sheath lengths (0.8)1-2(2.5) times blade lengths;

collars smooth, glabrous;

ligules 2-5(6) mm, usually smooth, ligules of proximal leaves sometimes scabrous, obtuse, those of the distal leaves acute;

blades 4-12(18) cm long, (2)3-7 mm wide, flat or loosely folded, glabrous, both surfaces smooth or the adaxial surfaces sparsely scabrous, apices broadly prow-shaped, cauline blades subequal, flag leaf blades 3-10 cm.

mainly intravaginal, some extravaginal.

all or mainly extravaginal.

1.5-6 cm, erect, compact, ovoid, contracted, infrequently interrupted, congested, with 15-50 spikelets;

nodes with 1-2 branches, internodes densely hispidulous;

branches 0.5-2 cm, erect, stiff, terete to weakly angled, densely hispidulous, with 1-5 spikelets.

(4)7-15(20) cm, lax, loosely contracted or open, moderately congested, with (15)20-100 spikelets and 2-4(5) branches per node;

branches 3-8 cm, ascending or eventually spreading, flexuous, terete or weakly angled, usually sparsely scabridulous or scabrous, infrequently moderately densely scabrous, with (3)5-15(30) spikelets moderately crowded in the distal 1/2.

7-12 mm, lengths to 3 times widths, laterally compressed, not sexually dimorphic;

florets 3-6;

rachilla internodes usually shorter than 0.5 mm, smooth, glabrous.

(5)6-9(12) mm, lengths to 3 times widths, laterally compressed, sometimes bulbiferous;

florets 2-5, infrequently bulb-forming;

rachilla internodes smooth or sparsely hispidulous.

broadly lanceolate, 1/2 as long as to subequal to the adjacent lemmas, distinctly keeled;

lower glumes 3-veined;

upper glumes 4-4.5(7+) mm, 3-veined;

calluses usually with a crown of hairs, sometimes glabrous or diffusely webbed;

lemmas 5-7.5 mm, lanceolate, 5-veined, distinctly keeled, keels, marginal veins, and sometimes the lateral veins short- to long-villous or softly puberulent, rarely glabrous, lateral veins moderately prominent, intercostal regions smooth, glabrous, margins glabrous, apices acute;

palea keels scabrous to pectinate-ciliate, intercostal regions glabrous;

anthers vestigial (0.1-0.2 mm) or (2)2.5-3.5 (4) mm.

subequal in length and width, usually nearly equaling the adjacent lemmas, lanceolate to broadly lanceolate, distinctly keeled, keels sparsely to moderately scabrous distally, lateral veins prominent;

lower glumes (4)4.5-7 mm, 3-veined: upper glumes (4)4.5-7(8) mm, 3(5)-veined;

calluses dorsally webbed, hairs 1/3 – 2/3 times the lemma length, copious;

lemmas (4)5-8 mm, lanceolate to broadly lanceolate, green or purple, distinctly keeled, keels and marginal veins long-villous, lateral veins prominent, usually softly puberulent to short-villous, intercostal regions sometimes hispidulous, infrequently softly puberulent or short-villous proximally and hispidulous in the central 1/3, sometimes merely muriculate proximally and scabrous distally, sometimes densely scabrous throughout, rarely glabrous and nearly smooth proximally and sparsely scabrous distally, margins broadly hyaline, glabrous, apices acute;

palea keels scabrous, sometimes softly puberulent at midlength, intercostal regions broad, distinctly hispidulous or softly puberulent;

anthers 1.5-2.5 mm.

= 28.

= 42, 43, 44, 45, ca. 46, 49, 56, ca. 58, 63, ca. 64, ca. 65, 66, 67, 68, 69, 70, ca. 71, ca. 72, ca. 73, 74, 75, 76, 77, 78, 80, ca. 82, ca. 84, ca. 87, ca. 100.