Flora of North America species comparison

10-40 cm, suberect, branching, fully or mostly emergent.

annual, 20-500 cm tall, aerenchymatous, sometimes floating.

mostly basal or scattered along the culms, not conspicuously floating or streaming in the current;

sheaths glabrous or ciliate;

ligules to 5 mm, lanceolate, acuminate;

blades 3-30 cm long, 0.5-4 mm wide, glabrous, sometimes scabridulous.

aerenchymatous;

auricles present or absent;

ligules membranous or scarious, sometimes absent;

pseudopetioles sometimes present;

blades with parallel veins, cross venation not evident;

abaxial blade epidermes with microhairs and transversely dumbbell-shaped silica bodies;

first seedling leaf without a blade.

panicles.

usually panicles, sometimes racemes or spikes;

disarticulation below the spikelets, not occurring in cultivated taxa.

laterally compressed or terete, with 1 bisexual or unisexual floret, sometimes with 2 sterile florets below the sexual floret, these no more than 1/2 (9/10) the length of the fertile floret;

unisexual spikelets in the same or different panicles;

rachillas not prolonged.

absent or highly reduced, forming an annular ring or lobes at the pedicel apices;

sterile florets 1/8 – 1/2 (9/10) as long as the spikelets;

fertile lemmas 3-14-veined, membranous or coriaceous, apices entire, unawned or with a terminal awn;

paleas similar to the lemmas, 3-10-veined, 1-keeled;

lodicules 2;

anthers usually 6(1-16);

styles 2, bases fused or free, stigmas linear, plumose.

usually caryopses, sometimes achenes, ovoid, oblong, or cylindrical;

embryos of the F+FP or F+PP type, small or elongate, with or without a scutellar tail;

hila usually linear, x = 12, 15, 17.

1-1.3 mm, broadly ellipsoid to subglobose, smooth, lustrous.

panicles 1-3 cm, terminal, with 10-25 spikelets; staminate florets 3.5-8 mm, caducous;

lemmas lanceolate, 5-veined;

paleas similar, 3-veined;

anthers 6, 2-5 mm.

panicles to 7 cm, arising from the lower to middle nodes of the culms, partially exserted from the sheaths, with 10-25 spikelets;

branches filiform, spreading to reflexed; pistillate florets 2-2.5 mm, caducous;

lemmas 7-14-veined, erose to acuminate or caudate;

paleas similar to the lemmas, 5-10-veined;

stigmas 2-3 mm.

= 24.