Flora of North America species comparison

cauline;

sheaths usually shorter than the internodes, lowermost sheaths appressed-pilose basally;

collars glabrous;

ligules less than 0.5 mm;

blades usually 4-12 cm long, 0.5-1.5 mm wide, flat or loosely involute, somewhat lax, glabrous or scabridulous, pale green.

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.

spicate or racemose, (5)7-20 cm long, 2-4 cm wide;

primary branches rarely developed.

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.

divergent, pedicels with axillary pulvini.

appressed.

unequal, glabrous, brownish-green with a purple tinge;

lower glumes (9)12-22(28) mm, 3-7-veined, midvein extended into a 1-13 mm awn between 2 delicate setae;

upper glumes (7)11-20(24) mm, 1-veined;

calluses 0.5-2 mm;

lemmas (9)12-22(23) mm, glabrous, light-colored, often mottled;

awns (8)12-65(70) mm, subequal, spreading;

anthers usually 1 and less than 0.5 mm, rarely 3 and 3-4 mm.

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.

8-14 mm, brown.

4-5 mm, chestnut brown.

25-55 cm, erect or geniculate at the base, highly branched.

60-120 cm, stiffly erect, unbranched.

= 22.

= unknown.