Flora of North America species comparison

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

annual, sometimes woody, hollow or solid.

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.

distichous;

sheaths open;

auricles sometimes present;

abaxial ligules absent;

adaxial ligules membranous, scarious, or of hairs;

pseudopetioles sometimes present;

blades rarely cordate or sagittate at the base, venation parallel;

mesophyll not radiate;

adaxial palisade layer usually absent;

fusoid cells sometimes present;

arm cells absent or present;

Kranz anatomy not developed;

midribs simple or complex;

adaxial bulliform cells present;

stomates with dome-shaped or triangular subsidiary cells;

bicellular microhairs present, terminal cells tapered;

papillae sometimes present.

panicles.

panicles, racemes, or spikes, rarely with bracts other than those of the spikelets;

disarticulation usually above the glumes, sometimes beneath the spikelets or at the base of the primary branches.

bisexual or unisexual, with 1 pistillate or bisexual floret, sometimes with 1-2 sterile florets below the functional floret.

absent or 2;

lemmas without uncinate hairs, sometimes terminally awned, awns single;

paleas well-developed, lacking in sterile florets;

lodicules 2, usually membranous, rarely fleshy, heavily vascularized;

anthers (1)3-6(16);

ovaries glabrous, without an apical appendage;

styles 2, free to the base to fused throughout, 2-branched.

caryopses or achenes;

hila long-linear;

endosperm without lipid, usually containing compound starch grains, rarely with simple starch grains;

embryos to 1/3 the length of the caryopses;

epiblasts usually present;

scutellar cleft usually present;

mesocotyl internode absent or very short;

embryonic leaf margins usually overlapping.

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.

=12 (10,15,17).

= 24.