Flora of North America species comparison

(2)3.5-45 cm.

(2)5-65 cm, herbaceous, usually rooting at the lower nodes;

nodes and internodes glabrous.

cauline;

sheaths open, usually shorter than the internodes, mostly glabrous but long-ciliate at the edges of the collar;

ligules membranous, truncate, ciliate;

blades usually flat, margins ciliate.

(1)2-13 cm long, (3)4-8 mm wide;

rachises pubescent;

branches (0.5)0.7-2.7 mm, pubescent, with 2(3) spikelets, axes occasionally extending past the distal spikelets;

proximal internodes 0.2-0.6(0.7) mm, shorter than the second internodes.

terminal, exceeding the upper leaves, narrow, cylindrical panicles;

branches 0.5-5 mm, resembling burs, with 2-5 spikelets;

disarticulation at the base of the branches.

crowded, attached individually to the branches, with 1 floret;

proximal spikelet(s) bisexual, larger than the distal spikelet(s);

terminal spikelets often sterile.

unequal;

lower glumes absent or minute, veinless, membranous;

upper glumes usually exceeding the florets, 5-7-veined, with 5-7 longitudinal rows of straight or uncinate spinelike projections;

lemmas 3-veined;

paleas 2-veined, hyaline, membranous, x = 10.

(0.9)1.2-2 mm long, 0.4-0.8 mm wide.

0.5-1 mm;

blades (0.5)0.7-8.5 cm long, 1.2-5 mm wide, glabrous.

spikelets (1.8)2^.3 mm;

second spikelets (0.8)1-3.9 mm, sometimes sterile.

glumes 0.1-0.6 mm, membranous, minutely pubescent;

upper glumes 1.8-4.3 mm, minutely pubescent, 5-veined, rarely with 1-2 additional veins adjacent to the midvein;

glume projections (4)6-14, in 5 rows, (0.2)0.3-1 mm, uncinate;

lemmas (1.5)1.8-3.1 mm, sparsely pubescent on the back, midveins occasionally excurrent to 0.6 mm;

paleas (1.3)1.5-2.4 mm;

anthers 3, 0.4-0.6 mm, yellow, occasionally purple-or green-tinged.

= 20.