Flora of North America species comparison

10-40 cm, highly branched above the base in age;

internodes glabrous or pubescent, sometimes nearly lanose.

45-100 cm, unbranched or sparingly branched.

cauline;

sheaths shorter than the internodes, glabrous or puberulent;

collars glabrous or pubescent at the sides;

ligules 0.5-1 mm;

blades usually less than 6 cm long, 0.5-1 mm wide, pale green, involute, glabrous or puberulent abaxially.

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 or racemose, 5-10 cm long, 1-2 cm wide, with few spikelets;

rachis nodes glabrous or with straight hairs;

primary branches 1-2 cm, appressed, without axillary pulvini.

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.

appressed.

unequal, 1-2-veined;

lower glumes 4-10 mm;

upper glumes 7-15 mm;

calluses about 1 mm;

lemmas 5-7 mm, purple or mottled, junction of the lemma and awns evident;

awns twisted together basally into a 4-26 mm column, free portions 12-50 mm, those of the central and lateral awns similar in length, curved to arcuate basally, straight and divergent distally, disarticulating at the base of the column at maturity;

anthers 3, about 2 mm long.

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.

4-5 mm, including the delicate style column.

= 22.

= unknown.