This introduced perennial grass is 1½2½' tall, producing both basal leaves and alternate leaves along its unbranched flowering culms. The slender culms are light green, terete to slightly flattened, and glabrous. The alternate leaves are 2-6 mm. across and 2-5" long; they are medium green, hairless, and ascending to widely spreading. The tips of the leaves are hull-shaped. The basal leaves are similar to the alternate leaves, except they are usually more long and floppy. The basal leaves are partially evergreen, while the flowering culms and alternate leaves die down after the grains ripen. The open sheaths are medium green, veined, and hairless. Each culm terminates in a panicle of spikelets about 3-6" long. The overall shape of the panicle is oblongoid-pyramidal or narrow-pyramidal. The central axis (stalk) of the panicle, its lateral branches, and branchlets are very slender and glabrous. Lateral branches of varying length occur in whorls of 1-5 along the central axis; they are ascending to widely spreading. The lateral branches divide and subdivide into smaller branchlets that terminate in spikelets about 4-6 mm. long. Each spikelet consists of a pair of glumes and 3-5 lemmas with florets. The glumes are about 2.5 mm. long, narrowly ovate, membranous along their margins, and convex along their outer sides; each glume has 1-3 fine nerves. The lemmas are about 3.0 mm. long, narrowly ovate, membranous along their margins, and convex along their sides; each lemma has 5 fine nerves. The mid-nerve and marginal nerves are finely pubescent along the lower half of each lemma, while the intermediate nerves are hairless. At the base of each lemma, there is a small tuft of fine webby hairs. Each floret has 3 anthers and 2 plume-like stigmata. The blooming period usually occurs from late spring to early summer and the florets are wind-pollinated. Each fertile lemma produces a single elongated grain about 2 mm. long. The root system is fibrous and long-rhizomatous. This grass often forms colonies of plants from the rhizomes. There is some variability across different strains of this grass.