Flora of North America species comparison

20-250 cm;

internodes green, sometimes glaucous;

branches mostly erect, straight.

20-310 cm, erect, much-branched distally.

usually scabrous, sometimes smooth;

ligules 0.6-2.2 mm, sometimes ciliate, cilia to 0.9 mm;

blades 13-109 cm long, 2.9-9.5 mm wide, glabrous or sparsely to densely pubescent, hairs usually spreading, rarely appressed.

not aromatic;

ligules membranous, sometimes ciliate;

blades linear, flat, folded, or convolute.

10-600 per culm; subtending sheaths (2.0)2.9-4.4(6.5) cm long, (1.5)2.3-3.4(4.4) mm wide;

peduncles (1)6-14(60) mm, with 2(4) rames;

rames (1)1.7-2.5(3.5) cm, exserted or not at maturity, pubescence sparse basally and increasing in density distally within each internode.

terminal and axillary or a false panicle;

inflorescence units 1-600+ per culm;

peduncles initially concealed by the subtending leaf sheaths, sometimes exserted beyond the sheaths at maturity, with (1)2-5(13) rames;

rames not reflexed at maturity, axes slender, terete to flattened, not longitudinally grooved, usually conspicuously pubescent, with spikelets in heterogamous sessile-pedicellate pairs (the terminal spikelets sometimes in triplets of 1 sessile and 2 pedicellate spikelets), apices of the internodes neither cupulate nor fimbriate;

disarticulation in the rames, below the sessile spikelets.

usually longer than 3 mm, similar to the rame internodes in shape, length, and pubescence color, not fused to the rame axes.

spikelets 3-5 mm;

callus hairs 1-2.5 mm;

keels of lower glumes sometimes scabrous below midlength, usually scabrous distally;

awns 6-19 mm;

anthers 1(3), 0.5-1.5 mm, yellow, red, or purple.

spikelets bisexual, awned, with short, blunt calluses;

lower glumes 2-keeled, flat or concave, usually not veined between the keels, sometimes 2-9-veined;

anthers 1, 3(2).

spikelets vestigial or absent, sterile.

spikelets usually vestigial or absent, sometimes well-developed and staminate.

= 10.

= 20.