Flora of North America species comparison

25-90 cm.

20-126 cm, terete or weakly compressed.

closed for 1/2 - 3/4 their length, smooth or sparsely scabrous, margins not ciliate;

ligules 0.3-2.1 mm, smooth or sparsely scabrous, truncate to obtuse, ciliolate;

blades 0.6-3.5 mm wide, flat.

closed for (1/20)1/3 to about their full length, terete or weakly keeled, basal sheaths readily deteriorating;

ligules 0.1-3(4) mm, smooth or sparsely scabrous, truncate to obtuse, entire or lacerate, smooth or ciliolate;

blades smooth or scabrous, glabrous, apices narrowly prow-shaped.

mainly pseudointravaginal.

usually mainly pseudointravaginal, sometimes mainly extravaginal.

7.5-15(18) cm, lax, pyramidal, open, sparse;

nodes with 1-3(5) branches;

branches 3-8 cm, ascending, straight to spreading, angled, angles prominent, scabrous.

4-36 cm, erect or lax, pyramidal or lanceoloid, usually sparse, lower rachis internodes usually longer than (2)3 cm;

nodes with 1-10 branches;

branches ascending to spreading or eventually reflexed, lax or straight, angled, angles scabrous, with spikelets confined to the distal 1/5 – 1/3(1/2).

4-6.5 mm, laterally compressed;

florets 2-5;

rachilla internodes to 1 mm, smooth, glabrous.

2.5-8.2 mm, laterally compressed;

florets (1)2-5(6), normal, bisexual;

rachilla internodes smooth, usually glabrous, sometimes puberulent.

1/2-1/3 the length of the adjacent lemmas, distinctly keeled, keels scabrous;

lower glumes subulate to narrowly lanceolate, (1)3-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed;

lemmas (2.5)3.2-4.7 mm, lanceolate, green, distinctly keeled, keels and marginal veins long-villous, hairs extending up almost the whole keel length, lateral veins prominent, intercostal regions smooth, minutely bumpy, usually glabrous, rarely sparsely softly puberulent, apices acute, blunt, or pointed, white, not bronze;

palea keels softly puberulent at midlength, apices scabrous;

anthers (0.5)0.8-1.2(1.5) mm.

distinctly keeled, scabrous;

calluses terete or slightly laterally compressed, usually dorsally webbed, sometimes glabrous;

lemmas 2.1-5 mm, lanceolate to broadly lanceolate, distinctly keeled, glabrous or hairy, apices with narrow, clear or white margins;

palea keels scabrous, glabrous or with hairs over the keels;

anthers 3, 0.4-2(2.6) mm.

= 28.