Description

This plant is a summer annual that consists of a tuft of flowering culms and leaves about 2-6' tall. The slender culms are up to 0.5 mm. across, light to medium green, glabrous, and erect to ascending. About 1-4 alternate leaves are located toward the bottom of each culm. The narrow blades of these leaves are ¾-4' long and up to 0.5 mm. across; they are light to medium green, glabrous, and terete to slightly flattened. The leaf blades are ascending to widely spreading; their tips often turn brown in response to dry weather. Each culm terminates in an inflorescence consisting of 1-3 spikelets and 1-2 leafy bracts. The spikelets are up to 3 mm. (1/8') long and a little less across; they are ovoid to ovoid-globoid in shape and sessile. Each spikelet consists of numerous perfect florets and their scales, which are arranged in several tiers. Each floret consists of an ovary with a divided style and a single stamen; there are neither petals nor sepals. The outer scale of each floret is 0.5-1.0 mm. in length and elliptic to obovate in shape, tapering to a narrow point; it has a green central vein and membranous margins. There is also a hidden inner scale that is adjacent to the floret; it is about 0.1-0.2 mm. in length and membranous. Sometimes the inner scale is absent. Immature spikelets are light green, while mature spikelets are dark brown. There is an erect leafy bract up to 2' long that resembles an extension of the culm; there is usually a 2nd lateral bract that is shorter. The blooming period can occur from mid-summer into the fall. The florets are wind-pollinated. The florets are replaced by tiny achenes about 0.5 mm. long that are light brown, oblanceoloid in shape, and minutely reticulated. The achenes are without bristles; they are distributed by wind and water. The root system consists of a dense tuft of fibrous roots. This annual plant spreads by reseeding itself.