Flora of North America species comparison

(3)10-50(80) cm, often highly branched above the base.

45-100 cm, unbranched or sparingly branched.

cauline, glabrous;

sheaths shorter than the internodes, not disintegrating into threadlike fibers;

ligules 0.4-1 mm;

blades 2-14 cm long, 1-2.5 mm wide, flat to involute.

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.

panicles, 5-15(20) cm long, 0.5-3 cm wide, often interrupted below;

nodes glabrous or with straight, less than 0.5 mm hairs;

primary branches 1-4 cm, erect to ascending, without axillary pulvini, with 3-8 spikelets.

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.

crowded.

unequal, 1-veined, acuminate;

lower glumes 4-8 mm;

upper glumes 6-11 mm;

calluses 0.5-0.8 mm;

lemmas 6-9 mm, slightly keeled, midveins scabrous, junction with the awns not evident;

awns not disarticulating at maturity, flattened and straight to somewhat curved at the base, central rib flanked by equally wide pale wings;

central awns 7-15(20) mm;

lateral awns somewhat shorter, occasionally only 1-2 mm;

anthers 3, 0.3-0.7 mm.

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.