Comprehensive Description

Read full entry


This perennial grass produces both infertile and fertile shoots. Infertile shoots are up to 1' tall and semi-evergreen; they occur throughout the year, consisting of tufts of low leaves. During the spring and summer, fertile shoots develop, consisting of tufts of tall leafy culms about 2½–4' tall that are deciduous. These culms are terete, light green to reddish brown, glabrous, and erect. Several alternate leaves occur along the entire length of each culm. The blades of these leaves are up to 15 mm. across and 12" long; they are medium green, dark green, or bluish green, hairless on both their upper and lower sides, and rather floppy. The bases of these blades are narrowly auricled (with narrow ear-like lobes); these auricles clasp the culms. The leaf sheaths are light green, medium green, yellowish green, or reddish green; they are open toward their apices, hairless to sparsely short-pubescent, longitudinally veined, and often membranous along their margins. The ligules are white-membranous. Each fertile culm terminates in an erect floral spike (or spike-like raceme) about 2½–6" long; this inflorescence is densely covered on all sides with ascending spikelets that are sessile, or nearly so. Often, the floral spike is partially enclosed or barely exerted from the uppermost leaf. Each spikelet has a pair of glumes and a cluster of 2-4 lemmas. The glumes are linear-lanceolate, 8-15 mm. in length (excluding their awns), and 1.0–2.5 mm. across near their bases; their straight awns are about ½–1" (10-25 mm.) long. The lemmas are 6-10 mm. in length (excluding their awns) and their straight awns are 6-30 mm. long. When upper lemmas are present in a spikelet, they are a little smaller in size than the lower lemmas and often sterile. The outer surfaces of individual glumes are convex, 3-5 veined, and glabrous, scabrous (rough-textured from minute stiff hairs), or finely short-pubescent. The outer surfaces of individual lemmas are convex, 5-7 veined, and glabrous to finely short-pubescent. The florets of fertile lemmas have 2 stigmas and 3 white or pale yellow anthers. The blooming period occurs during the summer, lasting 1-2 weeks for a colony of plants. The florets are cross-pollinated by the wind. Afterwards, the floral spikes become tan-colored and the leaves of fertile shoots begin to wither away. The florets are replaced by long grains with adherent pericarps (one grain per fertile lemma). The root system is fibrous. This grass can tiller at the base, forming clonal offsets from the root system. Cultivation


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

© John Hilty

Source: Illinois Wildflowers


EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!