Flora of North America species comparison

1-12 cm, slender.

28-85 cm, erect or the bases decumbent, 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 about 1/15 – 1/5 their length, sometimes fused for a longer distance by a narrow hyaline membrane, terete, bases of basal sheaths glabrous, distal sheath lengths 0.8-1.5 times blade lengths;

ligules 0.5-3 mm, scabrous, usually lacerate;

blades scarcely reduced in length distally, 2-5 mm wide, flat, lax, apices narrowly prow-shaped, flag leaf blades 5-15 cm long.

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.

10-20 cm, erect, pyramidal, open, sparse, with 25-70 spikelets;

nodes with 1-3(5) branches;

branches 5-15 cm, ascending, straight, spreading to eventually reflexed, angled, angles mostly moderately to densely scabrous, with 5-15 spikelets.

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

florets 2-3;

rachilla internodes shorter than 1 mm, smooth.

4.5-6 mm, lengths 3.5 times widths, laterally compressed;

florets 2-3;

rachilla internodes, at least some, longer than 1 mm, smooth, glabrous.

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.

distinctly keeled;

lower glumes 1-3-veined;

upper glumes shorter than or subequal to the lowest lemmas;

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

lemmas 3.5-5 mm, narrowly lanceolate, distinctly keeled, smooth, glabrous throughout, lateral veins moderately prominent, apices acute to acuminate;

paleas smooth to scabrous over the keels;

anthers about 2 mm.

= 14.

= 56.