Flora of North America species comparison

20-70(112), often decumbent and rooting at the lower nodes.

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

keeled, usually sparsely pubescent with papillose-based hairs;

ligules 0.5-2.6 mm;

blades 2-11(14) cm long, 3-8(12) mm wide, usually with papillose-based hairs on both surfaces, sometimes glabrous.

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 4-13 spikelike primary branches, these subdigitate or on rachises to 6 cm;

primary branches 3-30 cm long, 0.7-1.5 mm wide, flattened and winged, wings more than 1/2 as wide as the midribs, lower and middle portion of the branches bearing spikelets in unequally pedicellate pairs, pedicels not adnate to the branches;

secondary branches rarely present.

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.

homomorphic, 1.7-3.4 mm long, 0.7-1.1 mm wide.

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

0.2-0.4 mm long, veinless;

upper glumes 0.9-2 mm, 1/3 – 1/2 as long as the spikelets, 3-veined, pubescent on the margins;

lower lemmas usually exceeded or equaled by the upper florets, sometimes exceeding them but by no more than 0.2 mm, glabrous, 7-veined, lateral (or all) veins scabrous throughout or smooth on the lower (1/3)1/2 and scabrous distally, 3 middle veins usually widely spaced, remaining veins on each side close together and near the margins;

upper lemmas 1.7-3 mm, yellow or gray, frequently purple-tinged when immature, often becoming brown at maturity;

anthers 0.5-0.9 mm.

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.

= 36, 28, 34, 54.

= 54, 72.