IUCN threat status:

Not evaluated

Comprehensive Description

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This native perennial plant is about 1½–3' long with its stems erect or ascending. It often forms loose tufts of culms and leaves; many of these shoots are vegetative and don't produce spikelets of flowers. The culms are light green, hairless, and 3-angled, while the alternate leaves are up to ¼" across and 16" long. About 6-10 leaves are produced per culm; these leaves are evenly spaced along the culm beneath the stalk of the inflorescence, if there is any; for vegetative shoots, these leaves are produced to the apex of the culm. Like the culms, the leaves are light green and hairless; they are also linear in shape and slightly rough along the margins. Fertile shoots produce a raceme of about 6-12 spikelets up to 2½" long. These spikelets are neither densely clustered together nor remote from each other. Staminate flowers often occur at the base of each spikelet, while the pistillate flowers are located above. Each spikelet is about 1/3" long and ovoid in shape, consisting primarily of a dense cluster of female flowers and their perigynia; it is rather conical at the bottom, but more rounded at the top. Each perigynium is about 3–5 mm. long, 1.2–1.8 mm. across, and flattened; it is ovate-lanceolate with a slender beak at its apex, while its bottom is slightly wedge-shaped. The upper half of the perigynium has a winged margin. The pistillate scale underneath each perigynium is smaller in size and lanceolate in shape; it has a green central vein and translucent margins (although it later becomes light brown). The perigynia are initially light green, but they later become light brown as the achenes mature. At the base of the lowest spikelet, there is slender green bract that is ½" in length or longer; the second lowest spikelet may have a conspicuous bract as well. The blooming period usually occurs during early to mid-summer, although some plants bloom later. The brown achenes are about 1.5 mm. in length, broadly oblongoid, and flattened; each achene also has a small beak at both its top and bottom. The root system consists of rhizomes and fibrous roots. Colonies of plants are often formed.


Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© John Hilty

Source: Illinois Wildflowers


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