Flora of North America species comparison

15-100 cm, slender to middling.

20-55 cm, erect or the bases decumbent, terete or weakly compressed;

nodes terete, 0-1 exserted.

closed for 1/4 - 3/5 their length, terete, smooth or sparsely scabrous, margins not ciliate;

ligules 1.5-4(6) mm, smooth to sparsely scabrous, obtuse to acute;

blades 1-4 mm wide, flat, thin, lax, soft, apices narrowly prow-shaped.

closed for 1/3-2/3 their length, terete, sparsely to moderately scabrous, glabrous or retrorsely hispidulous, bases of basal sheaths glabrous, distal sheath lengths 2.7-6.5(9.7) times blade lengths;

collars of at least some leaves usually sparsely hispidulous;

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

innovation blades to 40 cm, adaxial surfaces moderately to densely scabrous or hispidulous on and between the veins;

cauline blades steeply reduced in length distally, 1-3 mm wide, involute, moderately thick, soft, abaxial surfaces smooth, margins scabrous, apices narrowly prow-shaped, flag leaf blades 1-4.5 cm long.

mostly extravaginal.

extra- and intravaginal.

5-15 cm, lax, open, sparse;

nodes with 1-3(5) branches;

branches (2)3-8 cm, spreading to reflexed, capillary, usually angled, infrequently only sulcate or subterete, angles usually moderately densely scabrous, sometimes only sparsely so, with (3)4-15 spikelets.

4-8 cm, erect to nodding, lanceoloid to ovoid, loosely contracted, sparse, with 18-60 spikelets;

nodes with 1-2 branches;

branches 3-8 cm, ascending, lax, terete or weakly angled, moderately and sometimes coarsely scabrous, with 3-8 spikelets.

4-8 mm, lanceolate or narrowly lanceolate, green or partly purple to dark purple;

florets 2-5;

rachilla internodes smooth, glabrous.

6-9(11) mm, lengths to 3 times widths, laterally compressed, not sexually dimorphic;

florets 2-5(7);

rachilla internodes 1-2 mm, glabrous, scabrous, or sparsely to densely puberulent.

subulate to lanceolate, thin, distinctly keeled, keels usually scabrous;

lower glumes subulate to narrowly lanceolate, 1-veined;

upper glumes distinctly shorter than to nearly equaling the lowest lemmas;

calluses sparsely webbed;

lemmas 3-4 mm, lanceolate, often partly purple, distinctly keeled, thin, smooth, or with sparse hooks apically, keels and marginal veins softly puberulent to long-villous, hairs extending 1/4 - 2/3 the keel length, sometimes sparse, lateral veins and intercostal regions glabrous, margins glabrous, infolded, apices sharply acute to acuminate, usually bronze-colored;

palea keels nearly smooth, scabrous, or pectinately ciliate;

anthers 0.2-1.1 mm.

subequal, distinctly keeled;

lower glumes 3-veined;

calluses diffusely webbed, hairs about 1/2 the lemma length;

lemmas 4-6(7) mm, lanceolate, distinctly keeled, glabrous, smooth or sparsely to moderately finely scabrous, keels scabrous, lateral veins moderately prominent, margins glabrous, apices acute;

palea keels scabrous, sometimes softly puberulent at midlength;

anthers vestigial (0.1-0.2 mm) or 2-3 mm.

= 42.

= 28.