Flora of North America species comparison

60-120 cm, stiffly erect, unbranched.

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

basal or nearly basal;

sheaths shorter than the internodes, smooth and mostly glabrous abaxially, sometimes with a line of widely spaced, 0.5-1 mm hairs over the midvein, not disintegrating into threadlike fibers at maturity;

collars glabrous, sometimes with a few conspicuous hairs at the sides;

ligules 0.1-0.3 mm;

blades 15-50 cm long, 0.3-1 mm wide, tightly involute, stiff, yellow-green, abaxial surfaces villous on both sides of the midvein, at least on the basal portion, hairs 0.6-1.5 mm, adaxial surfaces densely scabrous or densely short pubescent.

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.

paniculate, 20-35 cm, 5-8 mm wide;

nodes glabrous;

primary branches 2-5 cm, appressed, without axillary pulvini, with 4-12 spikelets, spikelet-bearing to the base.

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.

appressed.

clustered on the distal 1/2 of the branches.

subequal, glabrous, light brown or tan, usually 1(2)-veined, bifid and awned, awns 1.5-2.5 mm;

lower glumes 7-10 mm;

upper glumes 6-9 mm;

calluses 0.4-0.6 mm;

lemmas 6-9 mm, glabrous, light-colored when young, reddish when mature, column 1-2 mm, not twisted, junction with the awns inconspicuous;

awns (7)10-15(22) mm, subequal, usually horizontally spreading or curving downward, not disarticulating at maturity;

anthers 3, about 3 mm, reddish-brown.

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.

4-5 mm, chestnut brown.

6-8 mm, tan.

= unknown.

= unknown.