Flora of North America species comparison

20-60(75) cm, erect, unbranched.

45-100 cm, unbranched or sparingly branched.

basal and cauline;

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

collars densely pilose, hairs 1-3 mm, cobwebby and tangled, often deflexed;

ligules less than 0.5 mm;

blades 4-28 cm long, less than 1 mm wide, usually involute, infrequently flat, usually arcuate, abaxial surfaces glabrous, adaxial surfaces glabrous or puberulent near the base, scabrous or puberulent distally.

cauline;

sheaths shorter than the internodes, glabrous except for occasional hairs at the summit;

collars glabrous, or with a few pilose hairs at the sides;

ligules about 0.5 mm;

blades 12-28 cm long, 1-3 mm wide, usually folded or loosely involute, light yellow-green, glabrous abaxially, puberulent adaxially.

paniculate, 10-20 cm long, 3-10(12) cm wide;

rachis nodes usually glabrous, sometimes with straight, less than 0.3 mm hairs;

primary branches 2-11 cm, stiffly ascending to spreading, with axillary pulvini;

secondary branches and pedicels with or without pulvini;

terminal spikelets often divergent.

dense panicles, (3)8-24 cm long, 2-4 cm wide, somewhat spirally twisted in age;

nodes glabrous or strigillose, hairs about 0.1 mm;

primary branches 2-4 cm, tightly appressed, without axillary pulvini, with 6-10 spikelets per branch.

clustered on the distal 1/2 of the branches.

equal or subequal, 1-veined, acuminate or awned, awns to 6 mm, brownish;

lower glumes 5-10 mm;

upper glumes 6-12 mm;

calluses 0.5-1 mm;

lemmas 7-13 mm, terminating in an obscure, narrow beak 1-4 mm long, 0.1-0.2 mm wide, junction with the base of the awns not evident;

awns 6-15 mm, not disarticulating at maturity, central and lateral awns similar in length and thickness, spreading to horizontal;

anthers 3, 1-3 mm, brown.

lanceolate, 1-veined;

lower glumes 3.5-4.5 mm, abruptly contracted to a 4-12 mm awn;

upper glumes 7-10 mm, gradually narrowed to a 10-12 mm awn;

calluses about 2 mm;

lemmas 5-6 mm, dark brown or purplish, terminating in a straight or twisted beak 7-30 mm long, about 0.2 mm wide, beak often disarticulating, no obvious zone of articulation developed, junction of the beak and awns sometimes evident;

awns usually unequal, strongly curved and twisted at the base, straight distally, sometimes disarticulating at maturity;

central awns (10)20-30 mm;

lateral awns 10-20(25) mm, at least 1/2 as long as and evidently thinner than the central awns;

anthers 3, about 1 mm, brown.

6-8 mm, tan.

4-5 mm, including the delicate style column.

= unknown.

= unknown.