Flora of North America species comparison

25-70 cm, erect or prostrate, unbranched or sparingly branched.

55-110 cm, erect, unbranched.

tending to be basal;

sheaths longer than the internodes, glabrous except at the summit;

collars densely pilose;

ligules 0.5-1 mm;

blades 5-20 cm long, 1-2 mm wide, flat to loosely involute, glabrous.

cauline;

sheaths shorter or longer than the internodes, glabrous, not disintegrating at maturity;

collars glabrous, or sparsely pilose at the sides;

ligules about 0.2 mm;

blades 5-25 cm long, 1-2 mm wide, flat or loosely folded, pale green, cauline leaves usually glabrous adaxially, innovation leaves pilose.

paniculate, 10-30 cm long, 6-25 cm wide, peduncles flattened and easily broken;

rachis nodes glabrous or with hairs, hairs to 0.5 mm;

primary branches 5-13 cm, stiffly divaricate to reflexed, with axillary pulvini, usually naked on the basal 1/2;

secondary branches usually well-developed.

spikelike racemes, 20-45 cm long, 1-2 cm wide;

nodes glabrous, with only 1 spikelet.

overlapping, usually appressed, sometimes divergent and the pedicels with axillary pulvini.

solitary, not overlapping.

8-12 mm, 1-veined, acuminate or shortly awned, awns to 4 mm;

calluses about 0.5 mm;

lemmas 8-13 mm long, the terminal 2-3 mm with 4 or more twists when mature, narrowing to 0.1-0.2 mm wide just below the awns, junction with the awns not evident;

awns (7)10-20 mm, not disarticulating at maturity;

central awns almost straight to curved at the base, ascending to somewhat divergent distally;

lateral awns slightly thinner and from much to slightly shorter than the central awns, ascending to divergent;

anthers 3, 0.8-1 mm.

9-11 mm, equal or the lower glumes slightly longer than the upper, narrowly oblong, often slightly falcate, tan to brown, 1-veined;

lower glumes occasionally with 1-2 faint lateral veins, awn-tipped, awns about 0.5 mm;

upper glume awned, awns 1-2.5 mm;

calluses 1-1.5 mm;

lemmas 7-10 mm, brown, lead-colored, or purplish, not beaked, junction with the awns not evident;

awns equally thick, not disarticulating at maturity;

central awns 14-20 mm, slightly longer than the lateral awns, strongly curved basally, distal portion reflexed;

lateral awns horizontal to reflexed;

anthers 3, about 4.5 mm, purplish.

8-10 mm, light brown.

4-5 mm, chestnut-colored.

= 22.

= unknown.