Home
Perennials, reeds (often forming dense stands), bisexual, rhizomatous and stoloniferous. Leaves: ligule a fringe of hairs; blade rolled in bud. Inflorescences paniculate, open, plumose, 20–60 cm long. Spikelets pedicellate, laterally compressed, with (2–) 3–10 bisexual florets, disarticulating between florets; rachilla with very long white hairs on the callus, prolonged beyond bisexual florets; incomplete florets both distal and proximal to bisexual florets. Glumes 2, very unequal, awnless, dorsally rounded, 3–5-nerved. Lemma narrow-attenuate, muticous to aristulate, rounded on back, 1–3-nerved. Palea conspicuous but relatively short. Hilum short. Embryo not waisted.
Aquatic or semi-aquatic perennials, with usually tall culms. Leaf-blades linear to narrowly lanceolate, flat, deciduous. Panicles large, dense, profusely branched, silkily hairy. Spikelets 3–11-flowered, the lowest floret ♂ or barren, the following hermaphrodite, the uppermost ± reduced; rhachilla bearded above with long silky hairs; glumes 3–5-nerved; lemmas narrow, rounded or slightly keeled on the back, glabrous; lowest lemma much longer than the glumes, 3–7-nerved, ± persistent; fertile lemmas acuminate, 1–3-nerved; lodicules 2; stamens 3, or 2 in the lowest floret.
Spikelets several-flowered, the rachilla densely covered with long fine silky hairs, disarticulating above the glumes and at the base of each segment between the florets, the first floret staminate or neuter, the others perfect; glumes unequal, narrow, acute, the first 1-nerved, the second 3-nerved; lemmas narrow, long-acuminate, each one successively smaller, the summits of all of them thus about equal; palea of staminate or neuter floret one-fourth as long as the lemma, that of the first fertile floret one-half as long as the lemma.
Perennial 5–12 dm, thickened at the nodes, the lower internodes very short, the lowest node often disarticulating; sheaths pilose at the throat; blades 2–4 dm × 3–6 mm; infl narrow, purplish, 1–3 dm, the ascending branches fascicled; glumes lanceolate, mostly 1-veined, the first 2.1–2.6 mm, the second 2.4–3 mm; lemmas glabrous, acute or acutish, 3.4–4.5 mm; rachilla-joints 1.3–2 mm, glabrous or hairy, usually short-pilose at the top; 2n=36. Native of Europe, intr. in fields, meadows, and roadsides from Me. to Pa., w. to Ont. and Wis.
Perennial 5–12 dm, thickened at the nodes, the lower internodes very short, the lowest node often disarticulating; sheaths pilose at the throat; blades 2–4 dm × 3–6 mm; infl narrow, purplish, 1–3 dm, the ascending branches fascicled; glumes lanceolate, mostly 1-veined, the first 2.1–2.6 mm, the second 2.4–3 mm; lemmas glabrous, acute or acutish, 3.4–4.5 mm; rachilla-joints 1.3–2 mm, glabrous or hairy, usually short-pilose at the top; 2n=36. Native of Europe, intr. in fields, meadows, and roadsides from Me. to Pa., w. to Ont. and Wis.
Lemmas heteromorphous, dorsally rounded, always glabrous, membranous; the inferior much longer than the inferior glume, usually persistent, 3 (sometimes 5-7-) nerved, linear-lanceolate, lanceolate-oblong or oblong, rather acute; the following (fertile), caducous, 3-1-nerved, linear lanceolate, with the apex acuminate or caudate-acuminate, thinly membranous; callus slender, straight or slightly curved, obtuse, densely bearded with long soft silky hairs.
Spikelets pedicelled, solitary, 3-11-flowered, laterally compressed, muticous, gaping at maturity; rhachilla disarticulating above the glumes and between the florets; inferior floret sterile or male, the following bisexual but the uppermost usually reduced.
Glumes 3-5-nerved, sometimes with cross-veins, subequal to unequal, persistent, membranous, lanceolate, obovate to oblong, dorsally rounded, apex acute, subacute or sometimes obliquely truncate.
Caryopsis oblong in outline, semiterete, loosely enclosed between the lemma and palea; hilum basal, oblong, small; embryo about 1/2 as long as the caryopsis.
Ovary glabrous; styles distinct, rather short; stigmas plumose, laterally exserted.
Stout aquatic or semi-aquatic perennials with creeping much-branched rhizomes.
Paleas much shorter than the corresponding lemmas, 2-keeled, oblong, hyaline.
Ligule a short membrane, densely ciliate along the apex.
Inflorescence a dense or loose many-flowered panicle.
Stamens 3 (2 in the inferior floret if present).
Culms rather tall, robust, sheathed.
Lodicules 2, glabrous.
