Scientific Name
Koeleria macrantha (Ledeb.) Schult. (Synonyms: Koeleria cristata; Koeleria nitida; Koeleria pyramidata)
Common Name(s)
Prairie junegrass, junegrass
Tribe / Family Name
Poeae
Flowering Period
May to July
Symbol
KOMA
Description
Prairie junegrass is a native cool-season perennial bunchgrass that reproduces from seeds and tillers. Culms usually range from 20–85 cm in height. Its inflorescence is a dense, spike-like panicle 4–27 cm long, interrupted at the base, and spreading at anthesis. Spikelets are 2.5–6.5 mm long, compressed, 2(3)-flowered, and rarely awned (but can sometimes have a short awn near the tip). Ligules are up to 2 mm long, membranous, obtuse to truncate, entire to erose, ciliolate, and puberulent abaxially.
General Info
This type of grass is not normally found in wetlands, but can grow in a wide variety of soils and can be located in semi-arid to mesic settings, sagebrush steppe, juniper woodlands, prairies, foothills, mountain valleys, and from plains to subalpine sites.
Similar Species
Prairie junegrass may be confused with other grasses, such as pinegrass (Calamagrostis rubescens), spike trisetum (Trisetum spicatum), and bluegrass (Poa) species, especially after their seed heads open up. One way to differentiate prairie junegrass from these other species is by inspecting their upper blade surfaces. The upper blade surfaces of pinegrass, spike trisetum, and bluegrass are not as coarsely veined or lack the “corduroy” appearance characteristic of prairie junegrass. Also, prairie junegrass is rarely awned (but sometimes shortly awned at tip), bluegrass species are unawned, while both pinegrass and spike trisetum are awned and quite evident along the backside of the lemmas.
Picture of growth habit.
Inflorescence is a dense, spike-like panicle (mature growth stage).
Close-up picture of spikelet.
Close-up picture of membranous ligule. Nolan Helmstetter, 2017.
Close-up picture of prominent leaf venation.
Illustration of prairie junegrass. USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. <i>An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols</i>. Charles Scribner's Sons, New York. Vol. 1: 245.