Flora of North America species comparison

25-95 cm, generally decumbent and rooting at the nodes.

annual, 10-300 cm, erect to decumbent;

internodes usually solid.

glabrous, extensively overlapping;

ligules 1-2 mm;

pseudopetioles 8-60 mm;

blades 7-30 cm long, 2-6.5 cm wide, narrowly elliptic to obovate, often acuminate, lacking intercostal fibrous bands, sometimes whitened beneath, lateral veins diverging from the midvein at a 4-8° angle.

10-40 cm, sparsely flowered;

branches solitary, with uncinate hairs, usually tipped with a staminate spikelet.

panicles, usually espatheate; ultimate branches with 1-2 pistillate spikelets and 1 terminal, staminate spikelet;

disarticulation beneath the pistillate florets and in the panicle branches.

unisexual, heteromorphic, usually in staminate-pistillate pairs on branchlets, with 1 floret;

rachillas not prolonged beyond the florets.

oblong to linear;

hila as long as the caryopses.

spikelets 2.5-3.5 mm, on 4-11 mm pedicels, subtending the pistillate spikelets, purple;

lower glumes 1-2 mm;

upper glumes 1.5-3.2 mm, 1- or 3-veined;

lemmas 2.5-3.5 mm;

paleas about 3/4 the length of the lemmas;

anthers 0.9-1.1 mm.

spikelets pedicellate, smaller than the pistillate spikelets, lanceolate to ovate, caducous;

glumes unequal;

lower glumes absent or much shorter than the upper glumes;

upper glumes somewhat shorter than the floret;

lodicules minute or absent;

anthers 6.

spikelets 7.5-12 mm, diverging slightly from the branches;

glumes brown;

lower glumes 5-7 mm, 5-7-veined;

upper glumes 6-8 mm, 3-5-veined;

lemmas 7.5-12 mm, linear-oblong, abruptly short-beaked, with uncinate hairs nearly to the base;

paleas equaling the lemmas.

spikelets sessile or shortly pedicellate, terete, sometimes inflated;

glumes unequal to subequal, shorter than the florets, scarious, entire, sometimes persistent;

lemmas chartaceous, becoming coriaceous, veins 5 or more, margins involute or utriculate, partly or wholly covered with uncinate hairs, not terminating in a branched awn;

paleas 2-veined;

lodicules absent;

styles 1, 3-branched.

scarious, sometimes ciliolate;

pseudopetioles present, twisted, placing the abaxial surface of the blades uppermost;

blades linear to oblong, not folding or drooping at night, lateral veins diverging obliquely from the midveins, cross venation evident.

= 12.

= 24.