Flora of North America species comparison

20-80 (100) cm tall, (1.5)2-3.5 mm thick, not or only slightly spongy, sometimes rooting at the lower nodes.

30-100 cm tall, 3-6 mm thick, spongy, usually decumbent and rooting at the lower nodes.

smooth to scabridulous, keeled, sometimes weakly so;

ligules 1-4 mm, usually rounded, sometimes acute to mucronate, erose-lacerate;

blades 12-30 cm long, 2-6 mm wide, abaxial surfaces smooth or scabridulous, adaxial surfaces scabridulous to scabrous.

smooth, weakly keeled;

ligules 5-9 mm;

blades 10-15 cm long, 3-8 mm wide, abaxial surfaces smooth, adaxial surfaces of the midcauline leaves often papillose.

6-25 cm long, 2.5-21 cm wide, pyramidal, open, nodding;

branches 5-13 cm, straight to lax, lower branches usually strongly divergent to drooping at maturity, sometimes ascending, with 15-50 spikelets, these often confined to the distal 2/3;

pedicels 0.5-7 mm.

often racemes, sometimes panicles, 15-35 cm long, 1-2 cm wide, open at anthesis, bases often enclosed in the flag leaf sheaths at maturity;

branches 5.5-8 cm (absent in racemose plants), solitary or in pairs, appressed, most branches with 1-3 spikelets, the lower branches sometimes with more than 3;

pedicels 1.5-2.5 mm.

1.8-4 mm long, 1.2-2.9 mm wide, laterally compressed, oval in side view, with 3-7 florets.

20-45 mm long, 2.5-3 mm wide, cylindrical and terete except slightly laterally compressed at anthesis, rectangular in side view, with 5-12 florets.

ovate, 1-1.5 times longer than wide, narrowing from midlength or above, veins terminating below the apical margins, apices often splitting with age;

lower glumes 0.5-1.2 mm, rounded to obtuse;

upper glumes 0.6-1.2 mm, acute or rounded;

rachilla internodes 0.1-0.6 mm;

lemmas 1.2-2 mm, ovate in dorsal view, veins raised, scabridulous over and between the veins, apices acute, prow-shaped;

paleas slightly shorter than to equaling the lemmas, lengths 1.5-3 times widths, keeled, keels not winged, tips pointing towards each other, apices narrowly notched between the keels;

anthers 2, (0.2)0.4-0.6 mm, purple or yellow.

unequal, acute;

lower glumes 1.3-4.5 mm;

upper glumes 3-7 mm;

rachilla internodes 2-3 mm;

lemmas 6-8.5 mm, scabridulous, 7-veined, gradually tapering from near midlength to the narrowly acute (< 45°) or acuminate apices;

paleas 0.7-3 mm longer than the lemmas, keels winged, tips parallel, intercostal region truncate, often splitting, apices appearing bifid, with 0.4-1 mm teeth;

anthers 3, 1-2 mm.

0.5-2 mm.

about 3 mm.

= 20 [reports of 28 are questionable].

= 40.