Flora of North America species comparison

with erect portion 10-85 cm, long-decumbent, rooting and branching at the lower nodes.

20-55 cm, erect, sometimes geniculate, not rooting at the lower nodes.

with papillose-based hairs or the upper sheaths glabrous;

ligules 1-4 mm;

blades 3-14 cm long, 2-9 mm wide, mostly glabrous but the adaxial surfaces with papillose-based hairs basally.

with (2)3-6 spikelike primary branches, these digitate or a few solitary branches below;

lowest nodes glabrous or with hairs less than 0.4 mm;

primary branches 6.5-21 cm long, 0.6-1.3 mm wide, axes winged, wings at least 1/2 as wide as the midribs, lower and middle portions bearing spikelets in unequally pedicellate pairs, pedicels not adnate to the branches;

secondary branches absent;

shorter pedicels about 0.2 mm;

longer pedicels to 2 mm.

with 3-6 spikelike primary branches on 6-10(15) cm rachises;

primary branches 1-6 cm, not or only narrowly winged, bearing spikelets in unequally pedicellate pairs, pedicels not adnate to the branch axes;

shorter pedicels 1.5-2 mm;

longer pedicels 3-4 mm.

2.6-3.7 mm, spikelet pairs dimorphic in their pubescence and venation pattern of the lower lemmas.

homomorphic, 2.5-3.1 mm (including pubescence), 2.4-3 mm (excluding pubescence).

absent or to 0.9 mm, deltoid or bifid;

upper glumes 1.7-2.8 mm, 1/2 - 3/4 as long as the spikelets, 3-veined;

lower lemmas 7-veined, veins smooth;

lower lemmas of shortly pedicellate spikelets with 3 equally spaced, glabrous or shortly pubescent central veins, lemma margins and the region between the 2 lateral veins with appressed or spreading, 0.5-1 mm hairs;

lower lemmas of long-pedicellate spikelets with unequally spaced veins, midvein well-separated from the 3 lateral veins, lateral veins crowded together near the margins, lemma margins and the region between the 2 inner lateral veins hairy with appressed or strongly divergent, 1-2 mm hairs, sometimes also with longer, glassy yellow hairs;

upper lemmas of all spikelets usually yellow or gray, sometimes light brown, at maturity;

anthers 0.5-0.6 mm.

0.3-1 mm, veinless;

upper glumes 2.1-3 mm (including pubescence), as long as or exceeding the upper florets by no more than 0.5 mm, 3-veined, densely appressed-pubescent, hairs 0.5-1 mm, white to purple, tapering or parallel-sided, not spreading at maturity;

lower lemmas 2.3-3.1 mm (including pubescence), as long as or exceeding the upper lemmas by up to 0.5 mm, 5-veined, veins equally spaced, intercostal regions densely appressed-pubescent, hairs 0.5-1 mm, white to purple, tapering or parallel-sided, not spreading at maturity;

upper lemmas 2.2-2.5 mm, brown when immature, dark brown at maturity.

2.1-3.4 mm.

sheaths tomentose;

culm sheaths glabrous or variously pubescent (puberulent, ciliate, or sparsely hirsute);

ligules (0.1)0.5-1(1.5) mm, ciliate;

blades 2-5.5 cm long, 2-3 mm wide.

= 54, 72.

= 36.