Indiangrass (woodgrass, bushy bluestem, wild oatgrass)
Sorghastrum nutans (L.) Nash

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habitinflorescencespikeletillustration

Indian grass was one of the principal grasses of the tall grass prairie that dominated the central United States prior to European settlement and in Iowa is still common along roadsides and in prairie remnants. The native range of Indian grass extends from Canada to Mexico. Indian grass seldom naturally forms pure stands, except in some lowlands, but is found as a member of both wet and dry prairie communities, and is often found growing with big bluestem (Andropogon gerardii). Indian grass is considered very attractive and is frequently planted alongside highways both as an ornamental and to control erosion. The grass provides high quality forage for wildlife and livestock and can produce excellent hay if cut before the flower stalks develop (Johnson and Nichols, 1970). Indian grass is relatively easy to establish from seed, and several cultivars are often used in combination with other warm season natives to provide mid- and late-summer pasture.

Like many other warm season grasses, Indian grass flowers from July through September in Iowa. The flowering heads (panicles) are much branched and usually slightly nodding, but they appear dense due to the many yellowish to golden-brown spikelets and the whitish, almost silvery hairs on the branches and spikelet stalks. If you clasp the base of a flowering head of Indian grass and run your hand upwards, you will note that it feels smooth and almost greasy, unlike the flowering heads of most other grasses, which are rougher to the touch.

Etymology: Sorghastrum is derived from the generic name of a different grass genus, Sorghum, which comes from the spoken Latin “suricum granum” = “grain from Syria”, while the Latin suffix “astrum” indicates inferiority or an incomplete resemblance; nutans = nodding and is also from Latin—it refers to the appearance of the flowering heads.

 

Plants perennial, with short, stout, scaly rhizomes. Culms 70-220 cm tall, 2-4 (-5) mm thick, hollow, erect; nodes pubescent with ascending hairs. Leaves with open sheaths, the lower sheaths usually hairy, the upper ones smooth; ligules 1.5-7 mm long, membranous; blades flat, usually smooth, 18-56 cm long, (4-) 5-11 mm wide. Flowering heads 14-30 (-35) cm long, 2-7 cm wide, moderately to very dense, yellowish to golden brown; branches with each joint bearing a fertile, awned spikelet paired with a hairy, sterile pedicel (the terminal spikelet with 2 sterile pedicels); branch joints densely covered with white hairs; the spikelet, pedicel, and branch joint disarticulating as a unit. Spikelets 5-8 mm long, with 1 fertile floret; glumes subequal, 5-8 mm long, lower glumes 7-9 veined, more or less densely covered with whitish hairs, upper glumes 5-veined; fertile lemmas membranous, bearing a stout, once-bent awn (6-) 8-17 mm long; anthers golden to reddish yellow. Chromosome number 2n = 20, 40, 80.

 

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