Flora of North America species comparison

to 3 m. Leaves mostly cauline, evidently distichous;

blades to 75 cm long, 1.5-6 cm wide.

to 3 m, erect, creeping, or floating, branched;

internodes solid.

not aromatic;

ligules membranous.

axillary, of 2(3) rames, 1 pistillate, the other(s) staminate, pistillate rames completely enclosed in indurate, globose to cylindric, modified leaf sheaths, termed involucres, from which the staminate rames protrude.

usually 8-12 mm, varying in color.

of functional pistillate spikelets 6-10 mm, hyaline below, 5-7-veined, with a 1-3 mm coriaceous beak.

more or less globose.

not fused to the rame axes, x = 5.

rames 10-35 mm, with 3-25 spikelet pairs, disarticulating at maturity;

spikelets 5-9 mm, dorsally compressed;

glumes exceeding the florets, with 15+ veins;

lower glumes elliptic to obovate, somewhat asymmetrical, margins folded inward, apices obtuse;

upper glumes lanceolate to narrowly elliptic, keels often winged, apices acute;

upper lemmas 5-8 mm, hyaline, elliptic to ovate, 3-veined;

upper paleas similar but 2-veined;

anthers 3-6 mm.

rames flexible, exserted from the involucre;

spikelets in pairs or triplets, 1 sessile, the other(s) pedicellate, reduced, or absent;

lower glumes chartaceous, with 15 or more veins, 2-keeled, keels winged above;

upper glumes similar, with 1 keel;

lower florets sometimes sterile;

upper florets staminate;

stamens 0 or 3;

lodicules 2.

rames each with 3 spikelets, 1 sessile and pistillate, the other 2 pedicellate and rudimentary;

sessile spikelets somewhat dorsally compressed;

glumes coriaceous, beaked;

stigmas protruding from the involucres.

= 20.