Flora of North America species comparison

2-20(45) cm, prostrate to erect, slender;

nodes terete, usually 1 exserted.

20-60 cm, slender, erect or the bases decumbent, terete or weakly compressed;

nodes terete, 1-2 exserted.

closed for about 1/3 their length, terete or weakly compressed, smooth;

ligules 0.5-3(5) mm, smooth, glabrous, decurrent, obtuse to truncate;

blades 1-10 cm long, 1-3(6) mm wide, flat or weakly folded, thin, soft, smooth, margins usually slightly scabrous, apices broadly prow-shaped.

closed from 9/10 their length to their entire length, terete, smooth or sparsely scabrous, glabrous, bases of basal sheaths glabrous, distal sheath lengths 0.18-0.8 times blade lengths;

collars smooth, glabrous;

ligules 3-6 mm, scabrous, acute to acuminate;

innovation blades similar to the cauline blades;

cauline blades gradually reduced in length distally, 1.5-2.5 mm wide, flat, thin, soft, smooth or sparsely scabrous, primarily over the veins, apices narrowly to broadly prow-shaped, flag leaf blades 8-12 cm.

intravaginal, innovations common, similar to the culms.

extravaginal, initiated as pinkish to purplish fleshy buds that persist as sets of short scales at the nodes of rhizomes and the proximal culm nodes, drying brownish and flabelliform after the shoots develop.

1-7(10) cm, lengths 1.2-1.6 times widths, erect;

nodes with 1-2(3) branches;

branches ascending to spreading or reflexed, straight, terete, smooth, with crowded or loosely arranged spikelets.

4-15 cm, erect, ovoid, sparse, with fewer than 15(20) spikelets;

nodes with 1-2 branches;

branches 1-4.5 cm, spreading to reflexed, slender, terete, sparsely to moderately scabrous, with 1-3 spikelets.

3-5 mm, laterally compressed;

florets 2-6;

rachilla internodes smooth, glabrous, concealed or exposed, distal internodes less than 1/2(3/4) the length of the distal lemma.

5-9 mm, lengths to 3.5 times widths, laterally compressed, not sexually dimorphic;

florets 2-6;

rachilla internodes smooth, sparsely hairy, hairs to 0.3 mm.

smooth, distinctly keeled, keels smooth;

lower glumes 1-veined;

upper glumes shorter than or subequal to the lowest lemma;

calluses glabrous;

lemmas 2.5-4 mm, lanceolate, distinctly keeled, smooth throughout, the keels, marginal veins, and, usually, lateral veins crisply puberulent to long-villous, rarely glabrous throughout, lateral veins prominent, intercostal regions glabrous, margins smooth, glabrous, apices obtuse to acute;

palea keels smooth, usually short- to long-villous, rarely glabrous;

anthers 0.6-1.1 mm, oblong prior to dehiscence, those of the upper 1-2 florets usually vestigial.

1/3 – 3/4(4/5) as long as the adjacent lemmas, keels sparsely scabrous;

lower glumes 3-veined;

calluses glabrous or webbed, hairs at least 1-2 mm;

lemmas 4-7 mm, lanceolate, distinctly keeled, keels and marginal veins glabrous or short-villous, lateral veins obscure, glabrous, finely scabrous, intercostal regions glabrous or sparsely softly puberulent, margins glabrous, apices acute;

palea keels scabrous, sometimes softly puberulent at midlength;

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

= 28.

= ca. 58.