junegrass (prairie junegrass, crested hairgrass, Koeler's grass)
Koeleria macrantha
(Ledeb.) Schult.

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June grass is one of the earliest maturing native grasses. Growth and flowering are usually complete by the end of June, at which time the plants go dormant until autumn or the following spring. While green, June grass is good forage for deer, elk, and all types of livestock. Because June grass is available earlier than other natives, it is easily overgrazed and decreases in abundance as grazing pressure increases (Johnson and Nichols, 1970). June grass is found throughout the temperate northern hemisphere in dry prairies and open woods, generally in sandy soil. In Iowa, June grass is most frequently found as member of drier prairie communities associated with little bluestem and the grama grasses, but it also occurs in mesic prairies and open woods. June grass occurs throughout Iowa but seems to be more common in the northern half of the state. The narrow, bright green, congested flowering heads to be seen in June make this grass stand out. June grass is most easily confused with the two Iowa species of wedgegrass (Sphenopholis intermedia and S. obtusata), but the more open flowering heads of S. intermedia and the much wider second glumes of S. obtusata separate them from June grass.

Etymology: The generic name Koeleria is after the German botanist Georg Ludwig (Georgius Ludovicius) Koeler (1765 – 1807); the Latin name macrantha comes from macranthus = large-flowered, and refers to the long, dense panicles.


Plants perennial, in small, scattered tufts, usually not forming dense stands. Culms (20) 30-75 cm tall, 1-1.5 mm wide, mostly glabrous, pubescent at the nodes and below the flowering heads. Leaves mainly basal; sheaths glabrous to short-hispid; ligules whitish, membranous, 0.5-2 mm long; blades 2-20 cm long, 0.5-3 (4.5) mm wide, flat while green, rolling up when dry, slightly rough, sometimes smooth or short-hispid. Flowering heads congested, 4-13 cm long, 0.5-1 (-2) cm wide. Spikelets (2.5-) 3.4-4.8 mm long, obovate, with 2 (-3) florets, laterally compressed, disarticulating above the glumes and between the florets; spikelet joints sparsely pubescent; glumes nearly equal, the second sometimes slightly longer, 3-5 mm, membranous, ovate with an acute apex, green, 1-3 nerved; lemmas 2.5-4 mm, membranous, shiny, usually glabrous, sometimes papillose, green when young but turning yellow at maturity, 5-nerved, the lateral veins faint, awnless or with the midvein prolonged as an awn of up to 1 mm. Chromosome number 2n = 14, 28.


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