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.

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.

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

primary branches rarely developed.

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.

divergent, pedicels with axillary pulvini.

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.

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.

8-14 mm, brown.

4-5 mm, including the delicate style column.

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

45-100 cm, unbranched or sparingly branched.

= 22.

= unknown.