Scientific Name
Elymus trachycaulus (Link) Gould ex Shinners ssp. trachycaulus (Synonyms: Agropyron trachycaulum)
Common Name(s)
Slender wheatgrass
Tribe / Family Name
Triticeae
Flowering Period
June to August
Symbol
ELTRT
Description
Slender wheatgrass is a native cool-season perennial bunchgrass (rarely producing rhizomes). Culms range from 30–150 cm in height. Its inflorescence is a slender, compact spike usually 8–30 cm long and not shattering at maturity. Spikelets are usually 9–17 mm long, closely imbricate, appressed along the rachis, 1 per rachis node, 3- to 9-flowered, and unawned or awned (the lemma awns up to 9 mm long and straight or sometimes curved). Auricles are short (up to 1 mm long) or absent. Ligules are very short (up to 0.8 mm long), membranous, obtuse to truncate, erose to ciliate, and glabrous.
General Info
This short-lived plant can normally be found in dry disturbed areas including roadsides, ditchbanks, and trailsides, occasionally near shores and streambanks, in meadows, woodlands, valley bottoms, foothills, plains, and montane to subalpine sites.
Similar Species
Slender wheatgrass can look similar to other tufted wheatgrasses or wildryes. Remember to look for its slender, closely imbricate seed heads, and spikelets that are unawned or awned (awns up to 9 mm long) when comparing it to other wheatgrasses or wildryes. Quackgrass (Elymus repens) is another species that has closely imbricate seed heads and spikelets that are unawned or awned (awns usually up to 5 mm long), but is a rhizomatous grass. Other rhizomatous grasses that may look similar to slender wheatgrass include intermediate wheatgrass (Thinopyrum intermedium), thickspike wheatgrass (Elymus lanceolatus ssp. lanceolatus), and western wheatgrass (Pascopyrum smithii). Additionally, wheatgrasses have one spikelet per rachis node, and wildryes have two or more spikelets per rachis node.
Picture of growth habit.
Close-up picture of spike inflorescence without awns.
Close-up picture of spike inflorescence with awns.
Close-up of spikelet. Note the unawned glumes and lemmas.
Close-up picture of spikelet. Note the awned glumes and lemmas.
Close-up picture of short, membranous ligule with auricles.
Illustration of slender wheatgrass. 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: 285.