Flora of North America species comparison

(15)30-100 cm, bases dull brown, glabrous;

nodes 2-4; branching intravaginal.

15-200 cm, not branching at the upper nodes;

basal branching intravaginal or extravaginal;

prophylls not evident, shorter than the leaf sheaths.

mostly glabrous, scabridulous, basal sheaths dull brown;

ligules 0.3-1 mm, truncate, erose, abaxial surfaces glabrous or almost so, ciliate, hairs longest (to 2 mm) towards the sides of the leaves, at the top of the sheaths;

blades (3)10-40 cm long, 0.5-1 mm wide, all alike, straight, erect, convolute, apices sharp.

mostly basal, not overwintering;

sheaths open to the base;

cleistogenes not present;

collars with tufts of hair on either side;

auricles absent;

ligules membranous, truncate or shortest in the center and rounded, edges usually ciliate, hairs at the outer edges often longer than the central membranous portion, ligules of the lower leaves glabrous or hairy, sometimes densely hairy, those of the upper leaves glabrous or sparsely hairy;

blades usually convolute, apices narrowly pointed, flag leaves longer than 10 mm.

(3)10-25(30) cm, narrow, cylindrical to lanceoloid, dense, from partially to wholly exserted at anthesis, erect or nodding distally;

branches strongly ascending.

panicles, often partially included in the upper leaf sheath;

branches straight.

5.5-11 mm.

5.5-24 mm, with 1 floret;

rachillas not prolonged beyond the floret;

disarticulation above the glumes, beneath the floret.

subequal, clearly exceeding the florets, linear-lanceolate, tapering to attenuate apices;

lower glumes 5.5-11 mm, 1-3-veined;

upper glumes 5-10.5 mm, 3-veined;

florets 2.3-3 mm, cylindrical to fusiform;

calluses 0.2-0.4 mm, acute to broadly acute, strigose;

lemmas hairy throughout, hairs on the lower portion about 0.15 mm, sparse, appressed, pappus hairs 3-4 mm;

awns 9-15 mm, twice-geniculate, first 2 segments twisted, scabridulous;

paleas 1-1.5 mm, sparsely pubescent, 2-veined, apices rounded;

lodicules 2, 0.6-1 mm;

anthers about 0.8 mm.

unequal, usually longer than the floret, sometimes shorter, hyaline, 0-5-veined;

florets narrowly lanceoloid, terete;

calluses 0.2-1.6(3) mm, acute, less than or equaling the floret diameter, antrorsely strigose distally, hairs white;

lemmas thickly membranous, basal 2/3 scabrous or shortly pubescent, distal 1/3 often bearing a pappus of ascending to strongly divergent 3-8 mm hairs, sometimes glabrous or with appressed hairs shorter than 1 mm, margins not or only slightly overlapping at maturity, apices not fused into a crown, lobes to 0.2 mm, with a single, terminal awn, awn-lemma junction conspicuous;

awns 9-45(80) mm, persistent or deciduous, scabrous, weakly once- or twice-geniculate, first segment scabrous or pilose, terminal segment glabrous or pilose, smooth or scabrous;

paleas 1/3 - 1/2 as long as the lemmas, flat between the veins, membranous to hyaline, glabrous or sparsely pubescent, 2-veined, veins poorly developed, apices rounded to irregular;

lodicules 2-3, the third, if present, reduced;

anthers 3.

1.8-2.2 mm long, 0.6-0.7 mm thick, cylindrical.

fusiform, not ribbed;

hila linear, x = unknown.