Flora of North America species comparison

(7) 35-150 cm, erect, not rooting at the lower nodes.

5-70 cm, erect or strongly geniculate at the first node, glabrous.

mostly basal, sometimes forming a dense 10-35 cm tuft;

sheaths glabrous;

ligules 2-13 mm, scarious, decurrent, obtuse to acute;

blades 5-30 cm long, usually at least some flat and 1-4 mm wide, the remainder folded or rolled and 0.5-1 mm in diameter, adaxial surfaces with 5-11 prominent ribs, ribs usually all papillose, scabridulous, or scabrous, sometimes puberulent, outer ribs sometimes more strongly so than the inner ribs.

mostly basal, sometimes forming a dense, moss-like tuft 5-20 cm in diameter;

sheaths smooth, glabrous;

ligules 1.5-8 mm, acute;

blades 0.5-8 cm long, usually strongly rolled and 0.5-1.3 mm in diameter, rarely flat and to 1.5(2) mm wide, abaxial surfaces smooth, adaxial surfaces with 3-5(6) ribs, ribs smooth, the outer ribs sometimes scabrous.

8-30(40) cm, 4-30 cm wide, usually open and pyramidal, sometimes contracted and ovate;

branches straight to slightly flexuous, usually strongly divergent, sometimes strongly ascending, lower branches often scabridulous or scabrous, particularly distally, with not or only moderately imbricate spikelets.

3.5-17 cm long, 1.5-9 cm wide, usually open and pyramidal, sometimes closed and ovate;

branches 0.5-6 cm, spreading to reflexed, flexuous, smooth.

2.5-7.6 mm, ovate to V-shaped, laterally compressed, usually bisexual, sometimes viviparous, bisexual spikelets usually with 2(3) florets, rarely with 1.

3.5-5.2 mm, shiny, purplish, with 2(3) florets.

lanceolate, acute;

lower glumes 2.7-7 mm, entire, 1-3-veined, midvein sometimes scabridulous, at least distally;

upper glumes 2-7.5 mm, 1-3-veined, lanceolate, midvein smooth or wholly or partly scabridulous;

callus hairs 0.2-2.3 mm;

lemmas 2-5(7) mm, smooth, shiny, glabrous, usually purple over less than 1/2 their surface, purple or green proximally, if green, often with a purple band about midlength, usually green or pale distally, usually awned, awns (0.5)1-8 mm, attached from near the base to about midlength, straight or geniculate, sometimes exceeding the glumes;

anthers 1.5-3 mm.

lanceolate, sometimes purplish over the proximal 1/2, acute to acuminate;

lower glumes 2.7-4.8 mm, 0.8-0.9 times the length of the spikelets, 1-3-veined, veins smooth;

upper glumes 3-5 mm, equaling or exceeding the lowest floret, 1-5-veined;

callus hairs 0.3-1 mm;

lemmas 2-4 mm, smooth, shiny, glabrous, sometimes purplish distally, apices rounded or truncate, erose, awns 0.8-2.5 mm, arising at or below midlength, straight, slender, only slightly or not exserted;

anthers 0.7-2.5 mm.

0.5-1 mm.

voucher specimens for these counts have not been examined.

= 18, 24, 25, 26-28, about 39, 52.

= 26, 28, 36, ca. 39.