Flora of North America species comparison

5-45 cm, slender, erect or spreading;

from a dense tuft of predominantly basal leaves, lower internodes short, upper 3-5 internodes elongate;

nodes glabrous or bearded;

internodes glabrous or pilose;

fall phase with spreading culms and branches arising from near the bases forming a dense, flat tuft.

20-100 cm, decumbent to erect, sometimes geniculate;

nodes usually glabrous, sometimes sparsely pilose or densely bearded with retrorse hairs;

internodes often purplish or olive green, lowest internodes usually glabrous, varying to sparsely pubescent;

fall phase usually branching freely, especially from the nodes above the middle, ultimately forming dense, reclining fascicles of divergent branchlets with numerous reduced, thin, often involute blades, secondary panicles often reduced, with few spikelets.

2-4;

lower cauline sheaths longer than the internodes, mostly glabrous or pilose with ascending hairs, margins finely ciliate;

ligules 0.2-2 mm, at low magnification appearing to be membranous and ciliate, at high magnification evidently of hairs that are coherent at the base;

blades 1.5-6 cm long, 3-8 mm wide, lanceolate, glabrous or softly pilose, margins with prominent papillose-based cilia, at least basally.

4-7;

sheaths usually shorter than the internodes, usually glabrous, occasionally the lower sheaths sparsely to densely soft-pubescent, sheaths of the uppermost leaves sometimes with whitish glandular spots between the prominent veins, margins of all sheaths glabrous or ciliate;

ligules absent or shorter than 1 mm, of hairs;

blades 3.5-14 cm long, 5-14 mm wide, usually thin, distant, spreading to reflexed or (occasionally) ascending, yellow-green to purplish, usually glabrous on both surfaces or (at least the lower blades) more or less densely and softly pubescent, bases constricted (in narrow-bladed subspecies) or narrowly subcordate (in wide-bladed subspecies), margins glabrous or ciliate basally, glabrous distally, blades of the flag leaves usually spreading.

1.1-2.1 mm, obovoid to broadly ellipsoid, glabrous or pubescent, hairs not papillose-based.

1.5-2.7 mm, usually ellipsoid or obovoid, green or purplish (at least at the base), glabrous or (less commonly) sparsely pubescent or puberulent, often prominently veined, obtuse to acute to beaked.

1/3 - 1/2 as long as the spikelets, acute to obtuse;

upper florets 0.8-1.7 mm, ellipsoid, subacute.

usually less than 1/3 as long as the spikelets, obtuse to acute;

upper glumes usually slightly shorter than or as long as the lower lemmas and upper florets (occasionally extending beyond the floret);

lower florets sterile;

upper florets 1.3-2 mm long, usually less than 1 mm wide, ellipsoid, subacute to obtuse.

rosettes poorly differentiated;

blades 1-5 cm, lanceolate, grading into the cauline blades.

rosettes well-differentiated;

blades ovate to lanceolate.

panicles short- to long-exserted;

rachises and branches often pilose.

panicles 3-12 cm, long-exserted, usually with many spikelets;

branches wiry, mostly spreading or ascending, usually glabrous, sometimes scabridulous.