Flora of North America species comparison

1-12 cm, slender.

20-40(75) cm, erect or the bases decumbent, not branching above the base, terete or weakly compressed;

nodes terete, proximal nodes usually not exserted.

closed for 1/6 – 1/4 their length, terete;

ligules 1-3 mm, milky white to hyaline, smooth;

blades 0.5-2 mm wide, flat or folded, or slightly inrolled, thin, without papillae (at 100x), apices narrowly prow-shaped.

closed for 2/5 – 1/2 their length, terete, glabrous, smooth or slightly scabrous, bases of basal sheaths glabrous, distal sheath lengths (1)1.2-3.5 times blade lengths;

collars smooth, glabrous;

ligules 1.5-4(6) mm, smooth, apices obtuse to acute, not ciliate;

blades 1-3.5(5) mm wide, folded or flat, innovation shoot blades involute, soft, abaxial surfaces glabrous, adaxial surfaces smooth or sparsely scabrous, frequently sparsely hairy with 0.2-0.8 mm hairs, slender, erect to appressed, curving, sinuous or straight, apices narrowly prow-shaped, cauline blades subequal, flag leaf blades 1.5-8 cm.

all or mainly intra-vaginal.

mainly extravaginal.

1-3 cm, erect, contracted, usually exserted from the sheaths;

branches to 1.5 cm, erect to steeply ascending, slender, sulcate or angled, smooth or the angles sparsely scabrous;

pedicels shorter than the spikelets.

5-9(17) cm, narrowly lanceoloid to narrowly pyramidal, loosely contacted to open, sparse, with 25-60 spikelets and 2-5 branches per node;

branches 1-3 cm, ascending to spreading, slightly flexuous to fairly straight, terete, smooth or sparsely scabrous, usually with 1-5 spikelets per branch, the spikelets moderately crowded in the distal 1/2.

3-4 mm, laterally compressed, green or anthocyanic;

florets 2-3;

rachilla internodes shorter than 1 mm, smooth.

4-6.5(8) mm, lengths to 3 times widths, laterally compressed;

florets 2-4(6);

rachilla internodes shorter than 1 mm, smooth, usually glabrous, rarely with a few hairs.

usually equaling or exceeding the lowest lemmas, sometimes also equaling or exceeding the upper florets, lanceolate to broadly lanceolate, distinctly keeled, keels smooth;

lower glumes 3-veined;

calluses glabrous;

lemmas 2.5-3 mm, lanceolate, distinctly keeled, thin, usually glabrous, keels and marginal veins rarely sparsely puberulent proximally, apices acute;

palea keels scabrous;

anthers 0.2-0.8 mm.

unequal to subequal, usually distinctly shorter than the adjacent lemmas, lanceolate, distinctly keeled, keels smooth to sparsely scabrous;

lower glumes 2.8-3.5 mm, narrowly lanceolate, (1)3-veined;

upper glumes 4-4.5(5) mm, distinctly shorter than to nearly equaling the lowest lemmas;

calluses dorsally webbed, webs copious, hairs at least 1/2 times the lemma length, sometimes secondary webs present under the marginal veins;

lemmas 3.7-4.5(5) mm, lanceolate, usually strongly purple, distinctly keeled, keels, lateral veins, and marginal veins copiously hairy, hairs cottony, lateral veins prominent, less hairy, intercostal regions glabrous, usually smooth or finely muriculate, sometimes sparsely scabrous distally, margins narrowly hyaline, glabrous, apices acute;

palea keels sparsely scabrous, long-villous at midlength, intercostal regions narrow, glabrous;

anthers 1.8-2.5 mm.

= 14.

= 56, ca. 70.