Flora of North America species comparison

1-12 cm, slender.

20-65 cm, erect or the bases decumbent, not branching above the base, terete or weakly compressed;

nodes terete, 1-2 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 1/2-1/3 their length, slightly compressed, keels moderately distinct, smooth or sparsely to moderately scabrous, glabrous, bases of basal sheaths glabrous, distal sheath lengths 1.5-4.4(5.7) times blade lengths;

collars smooth, glabrous;

ligules of cauline leaves 2-8 mm, smooth or scabrous, acute to acuminate, innovation ligules 2-5 mm;

innovation blades to 20 cm, otherwise similar to the cauline blades;

cauline blades gradually reduced in length distally, 1-3.5 mm wide, usually flat or folded, soft, thin, somewhat lax, smooth or sparsely scabrous, primarily over the veins and margins, distinctly keeled, apices narrowly to broadly prow-shaped, flag leaf blades (1.4)3-6(8) cm.

all or mainly intra-vaginal.

all or mainly extra vaginal.

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.

(2)4-10 cm, nodding, ovoid, sparse, with 20-50 spikelets, proximal internodes usually 1.8-3 cm;

nodes with 1-2(4) branches;

branches 1.5-4.5 cm, ascending to spreading, lax, terete to weakly angled, angles sparsely to moderately scabrous, with 2-7 spikelets.

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

florets 2-3;

rachilla internodes shorter than 1 mm, smooth.

(4)6-9(12) mm, lengths to 3.5 times widths, laterally compressed, not sexually dimorphic;

florets 3-8, usually unisexual;

rachilla internodes smooth or sparsely scabrous, usually glabrous, infrequently sparsely puberulent.

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.

3/5 – 4/5 as long as the adjacent lemmas, narrowly lanceolate to lanceolate, distinctly keeled, keels scabrous;

lower glumes 1-3(5)-veined;

calluses webbed, hairs over 1/2 the lemma length;

lemmas 4-6.5 mm, lanceolate, 5-7-veined, distinctly keeled, keels and marginal veins sparsely short- to long-villous, lateral veins moderately prominent, intercostal regions sparsely scabrous, glabrous, margins glabrous, apices acute;

palea keels scabrous;

anthers vestigial (0.1-0.2 mm) or 2.5-4 mm.

= 14.

=28.