Cord grass was one of the dominant grasses of the tall grass prairie region, although it is found in southern Canada and over a good portion of the eastern and central U.S. Now it is found primarily in wet ditches and near sloughs and in pothole prairie remnants. In Iowa, cord grass is found throughout the state, although it is not documented for several counties. Cord grass is one of the tallest native grasses, sometimes reaching ten feet in height but is often shorter under less than ideal conditions, particularly in dry years. It often grows in dense, nearly pure stands near the edges of wetlands, with the vigorous rhizomes and shade from the tall stems excluding most other species. Livestock do not readily eat cord grass, except for early in the spring when the plants are still tender, as the stems are quite coarse and the leaves have rough edges. However, the grass can make good hay if it is cut several times a year to prevent it from becoming coarse. Native Americans used cord grass leaves and stems to thatch their lodges before covering them with soil. Settlers also used the grass for thatching roofs and covering haystacks (Johnson and Nichols, 1970). In Iowa, cord grass flowers from mid-July to early September, but often only a few plants in a stand will produce flowering heads in any given year. As noted by Pohl (1966) and Runkel and Roosa (1999), this species produces viable seed only rarely, so propagation is by rhizomes. The densely unilaterally flowered and ascending branches of its flowering heads are distinctive, as are the sharp-edged leaf margins.

Etymology: Spartina from the Greek spartine = a cord made from Spartium junceum (Spanish broom), probably used as a name for this genus because of the tough leaves and stems; pectinata from the Latin pectinata = a comb, referring to the one-sided spicate branches of the panicle, which have a comb-like appearance.

Plants perennial, strongly rhizomatous; rhizomes stout, elongated and pointed, purplish or light brown, drying to white. Culms sturdy, 1-2.5 m tall, 6-10 mm thick. Leaves with the sheaths open, mostly glabrous, throats often long hairy; ligules 1-3 mm long; blades 20-80 cm long, 5-15 mm wide, tapering to a fine, hairlike tip, flat but rolling up when dry, glabrous, margins scabrous. Flowering heads (25-) 30-50 cm long, 2-6 cm wide, with 7-17 one-sided densely flowered branches, branches comb-like with 10-80 spikelets. Spikelets 12-16 mm long, with one fertile floret, disarticulation below the glumes; glumes shortly awned, unequal, keels scabrous to hispid, lower glumes 5-8 mm long, awned, upper glumes 12-14 (-16) mm, exceeding the floret, 3-nerved, awned, awns 3-8 mm; lemmas glabrous, 7-9 mm long. Chromosome number 2n = 42, 70, 84.