Perennial, rhizomatous; rhizomes extensively spreading. Culms reedlike, erect, leafy, 0.6–1.5 m tall, 6–8-noded. Leaf sheaths glabrous, not inflated; leaf blades 10–35 cm × 10–18 mm, tapering to a fine apex; ligule 2–3 mm. Panicle contracted, linear-oblong in outline, lobed, interrupted, 8–15 cm; branches short, erect, densely spiculate. Spikelets oblong, laterally compressed, 4–6 mm; glumes narrowly lanceolate, glabrous or puberulous, pale green streaked darker green or purplish, keel scabrid, wingless or very narrowly winged upward, apex sharply acute; sterile lemmas equal, subulate, 1.5–1.8 mm, villous; fertile lemma broadly lanceolate, 3–4 mm, appressed-pubescent upward, shiny; palea boat-shaped, keels ciliolate. Anthers 2.5–3 mm. Fl. and fr. Jun–Aug. 2n = 28.
"Colonial by rhizomes; culms stout, 7–15 dm; main blades usually 1–2 dm × 10–15(–20) mm; panicle 7–25+ cm, dense but branched or lobed, often lightly suffused with purple; glumes 4–6.5 mm, wingless, glabrous to scaberulous; sterile lemmas linear-subulate, evidently villous, 1–2 mm; fertile lemma 3–4.5 mm, appressed-hairy distally; 2n=14, 28, 35, 42. Streambanks, lake-shores, marshes, and moist ground; circumboreal, in Amer. from Nf. to Alas., s. to N.C., Kans., and Calif., more abundant westward. Ribbon-grass, with green- and white-striped lvs, is a horticultural variant."
Glumes 3.5–7.5 mm. long, acute, wingless or with a very narrow and inconspicuous wing on the keel; sterile florets 2, subulate, 1.2–2.3 mm. long, villous; fertile floret lanceolate, 2.7–4.5 mm. long, dull yellow to grey-brown, sparsely pubescent.
Perennial from scaly creeping rhizomes.
Panicle 7–40 cm. long, dense, lobed or interrupted, with short branches up to 5 cm. long, these spreading at anthesis but otherwise contracted about the main axis.
Leaf-blades up to 20 cm. long and 15 mm. wide.
Perennial, rhizomatous (rhizomes scaly, creeping), up to 1.5 m high. Leaf blades 50-200 mm long, 5-15 mm wide. Spikelets 3.5-7.5 mm long. Panicle 70-160 mm long, 10-30 mm wide, often interrupted in lower part; glumes wingless, gradually tapering to tip; female-fertile floret sparsely pubescent; sterile florets 2, 1.2-2.3 mm long.
Perennial; up to 1.5 m high; rhizomes scaly; creeping. Culms erect. Leaf blades 50-200 x 5-15 mm. Flowers: panicle compact; spike-like; 15-110 x 10-25 mm; occasionally interrupted at base; spikelets 3.5-7.5 mm long; glumes wingless to narrowly winged; gradually tapering to apex; female-fertile floret sparsely pubescent; sterile florets 2; ± equal in length; 1.0-2.5 mm long.
Marshes, riverbanks, swamp margins and damp hollows in upland areas.