Flora of North America species comparison

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

20-60 cm, unbranched.

mostly basal;

sheaths glabrous or sparsely ciliate near the throat, basal sheaths papery, becoming pale;

ligules to 0.5 mm, of hairs;

blades to 15 cm long, 1-1.5(3) mm wide, flat, lower leaves variously hispid or scabrous, upper leaves glabrous, with scabrous margins.

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.

6-10 cm, with (8)12-16(20) branches;

branches 5-11 mm, deciduous, pubescent, with (2)4-6 spikelets, axes extending about 5 mm beyond the terminal spikelets, apices entire;

disarticulation at the base of the branches.

appressed.

appressed, all alike, with 1-2 bisexual florets and 1 rudimentary floret.

silvery-hispid over and between the veins, at least basally, apices acute, acuminate, or shortly awned;

lower glumes 5-6 mm;

upper glumes 6-7 mm, sericeous over the veins and elsewhere, hairs about 0.5 mm, apices mucronate;

lowest florets bisexual, pistillate, or staminate;

lowest lemmas 6-7 mm, pubescent between the veins and over the midveins, midveins extending into acuminate or setaceous lobes about the same length as the lateral lobes, not flanked by membranous lobes, lateral veins extending from the lateral lobes for 0.5-2 mm;

lowest paleas as long as the lemmas, pubescent, acute to acuminate, unawned;

second florets usually staminate, pistillate, or bisexual (rarely rudimentary);

second lemmas 8-10 mm; usually well-developed, pubescent, lateral veins extended into 0.5-4 mm awns, midveins extended into a flattened, 1-5 mm awn;

second paleas as long as the second lemmas, pubescent, usually with 2 short awns;

third florets, if present, pubescent, variable, resembling the second floret, a 3-awned structure with 2 membranous scales, or a prolongation of the rachilla.

2.5-3 mm.

about 5 mm long, about 1.5 mm wide.

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.