Flora of North America species comparison

4-60 cm, outer culms of a tuft decumbent, sometimes geniculate, branched at the lower nodes.

15-65 cm, erect, geniculate, or decumbent, sometimes rooting at the lower nodes, usually branching from the aerial nodes.

glabrous or pubescent;

ligules 0.2-0.3 mm, membranous, ciliate;

blades 5-20 cm long, 1-5 mm wide, bases with papillose-based hairs on the margins, both surfaces glabrous or pubescent.

2.5-10.5 cm, with (1)4-15 branches;

branches 5-45 mm, deciduous, densely pubescent (at least basally), with 2-10 spikelets per branch, axes extending 2-10 mm beyond the base of the terminal spikelets, apices entire;

disarticulation at the base of the branches, the break forming a sharp tip.

4-14 cm, with (3)7-12 branches;

branches 10-20 mm, with 2-8 spikelets, extending 4-6 mm beyond the base of the terminal spikelets, apices entire;

disarticulation at the base of the branches.

appressed.

appressed, all alike, with 1 bisexual and 1 staminate (rarely rudimentary) floret.

glabrous, veins scabrous or strigose;

lower glumes 4-7 mm;

upper glumes 4-9 mm, mostly glabrous, sometimes scabrous or strigose over the veins, apices acute, unawned or awn-tipped, awns about 1 mm;

lowest lemmas 4.5-8 mm, usually glabrous, rarely pubescent basally, 3-awned, awns wide basally, central awns slightly longer than the lateral awns, often flanked by 2 membranous 0.5-1.5 mm lobes;

lowest paleas 6-8 mm, bilobed, often shortly 2-awned;

anthers 3-5.5 mm, usually orange or yellow, occasionally red or purple;

second lemmas 5.5-7 mm, glabrous, 3-awned, central awns 4-10 mm, often flanked by membranous lobes, lateral awns 2-10 mm;

second paleas 4-7 mm;

anthers smaller than those of the lowest florets;

rachillas prolonged beyond the second florets as a short bristle.

2.5-3 mm.

3-4 mm.

0.2-0.5 mm, membranous, lacerate or ciliate;

blades 2-5(9) cm long, 0.7-2 mm wide, flat or folded, adaxial surfaces sometimes with papillose-based hairs, margins usually with papillose-based hairs near the ligules.

spikelet on each branch with 1 floret;

lower glumes 1.5-3.5 mm, glabrous, narrow to subulate;

upper glumes 5.5-6.2 mm, densely pubescent, at least on the basal 1/2;

lemmas 5.8-6 mm, acuminate, unawned;

lowest paleas almost as long as the lemmas, bifid, glabrous;

rachillas prolonged beyond the florets for about 0.5 mm.

spikelets with 1 bisexual and 1 rudimentary floret, glumes unequal, glabrous, minutely scabrous on the keels; narrowly acute or acuminate;

lower glumes 1.5-2 mm;

upper glumes 5-6 mm, glabrous or sparsely pubescent basally, often divergent;

lowest lemmas 6-8 mm, veins pubescent, lateral veins excurrent as short (to 1 mm) awns, acuminate, midvein extended into a setaceous tip or a short awn;

lowest paleas 5-7 mm, bifid, veins often excurrent as short awns;

anthers about 2.5 mm, yellow or yellow and red;

distal florets reduced to a pubescent, 3-awned, awn column, awns 2-7 mm, exserted.

= 40.

= 20, 40, 60.