Flora of North America species comparison

7-35(60) cm, erect or decumbent.

10-250 cm, usually erect, rarely prostrate, glabrous.

rounded below, margins and apices hairy, hairs to 3 mm;

ligules 0.3-1 mm;

blades 2-12(20) cm long, 2-6 mm wide, flat, abaxial surface glabrous, adaxial surface scabridulous, sometimes sparsely hispid, margins ciliate-pectinate.

open, usually glabrous, often ciliate at the apices;

ligules of hairs;

blades flat, folded, involute, sometimes terete.

4-15(18) cm long, 0.3-6 cm wide, open (contracted when immature), pyramidal;

lower nodes with 7-12(15) branches;

primary branches 0.5-4.5 cm, spreading 30-90° from the rachis, with elongated glands, without spikelets on the lower 1/3 – 1/2, secondary branches appressed;

pedicels 0.1-0.5 mm, appressed.

terminal, open or contracted panicles, sometimes partially included in the uppermost sheath.

1.2-1.8 mm, plumbeous or brownish, often secund along the branch.

rounded to laterally compressed, with 1(-3) floret(s) per spikelet;

disarticulation above the glumes.

unequal, ovate to obovate, membranous;

lower glumes 0.3-0.7 mm, without midveins;

upper glumes 1.2-1.8 mm, at least 2/3 as long as the florets, often longer;

lemmas 1.2-1.7 mm, ovate to elliptic, membranous, glabrous, acute;

paleas 1.1-1.6 mm, ovate to elliptic, membranous, glabrous;

anthers 0.2-0.4 mm, yellowish or purplish.

0-1-veined;

calluses poorly developed, usually glabrous;

lemmas membranous or chartaceous, 1(3)-veined, unawned;

paleas glabrous, 2-veined, often splitting between the veins at maturity;

anthers (2)3.

0.6-1 mm, obovoid, faintly striate, light brownish.

utricles or achenes, ellipsoid, obovoid, fusiform, or quadrangular, pericarp free from the seed, becoming mucilaginous when moist in most species, remaining dry and partially adherent to the seed in 5.

and 5.

.

spikelets occasionally present in the lower leaf sheaths, x = 9.

= 24, 36, 54.