Flora of North America species comparison

to 3 m, erect, usually at least partly immersed.

annual, sometimes woody, hollow or solid.

glabrous or with scattered hairs;

ligules 3-16 mm, upper ligules truncate, lanceolate or triangular, erose;

blades 20-60 cm long, 3-21(40+) mm wide, glabrous, margins glabrate or scabrous.

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.

24-60 cm long, 1-20(40) cm wide;

branches unisexual.

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.

6-30 mm long, 0.6-2 mm wide.

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.

branches ascending or divergent;

pedicel apices 0.2-0.4 mm wide.; staminate spikelets 6-17 mm, lanceolate, acuminate or awned, awns to 2 mm.

branches mostly appressed or ascending, a few sometimes divergent;

pedicel apices 0.7-1.2 mm wide.; pistillate spikelets 8-33 mm long, 1-2.6 mm wide, lanceolate or oblong, coriaceous or indurate, lustrous, glabrous or with lines of short hairs, apices usually hirsute and abruptly narrowed, awned, awns to 10 cm;

lemmas and paleas remaining clasped at maturity; aborted pistillate spikelets 0.6-2.6 mm wide.

=12 (10,15,17).

= 30.