Flora of North America species comparison

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

10-50 cm, erect, unbranched.

smooth, striate;

ligules 0.2-0.3 mm, membranous, ciliate;

blades 4-12(17) cm long, 1-2 mm wide, abaxial surfaces sparsely short pubescent, bases with papillose-based hairs on the margins, similar hairs also present on both surfaces.

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.

3-6 cm, with 6-8 branches;

branches 8-16 mm, hairy, becoming more sparsely so distally, with 2-6 spikelets, axes terminating beyond the base of the terminal spikelets, apices deeply bi- or trifurcate;

disarticulation at the base of the branches.

appressed.

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

lanceolate, veins pubescent, apices acuminate;

lower glumes 3-4 mm;

upper glumes about 6 mm, pubescent over the veins, hairs about 0.7 mm, apices bilobed, awned from the sinuses;

lowest lemmas 2.5-4 mm, glabrous or sparsely pubescent on the veins, 3-awned, awns wide basally, forming 3 triangular lobes, central awns flanked by 2 membranous 0.5-1.5 mm lobes;

lowest paleas 4-5 mm, bilobed, veins often excurrent;

second lemmas glabrous, 3-awned, awns 5-10 mm;

second paleas 2-lobed, unawned;

third lemmas similar to the second lemmas but smaller and without paleas.

2.5-3 mm.

(2) 3.5-3.7 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.

= 40.