Pictured above: Elytrigia repens
At one time included in the more widespread genus Agropyron, this is a small group of perennial grasses with creeping rhizomes. The inflorescence is a spike with one spikelet per node. Spikelets have several florets and are arranged in such a way that the widest side abuts the rachis of the inflorescence (as distinguished from the genus Lolium, the ryegrasses, in which the spikelets are placed edgewise to the rachis).
There are 2 species in MN; 1 is native.
Elytrigia repens (eh lih trig' ee ah ree' pens)
- Synonyms: Agropyron repens
- Common names: quack grass, witch grass
- Origin and habitat: Introduced from Eurasia and apparently with early settlers; a ubiquitous weed occurring in disturbed habitats.
- Identifying characters: A moderately tall (5-10 dm) perennial with widely spreading rhizomes with long internodes. Leaf blades are somewhat keeled near the collar area; the uppermost leaf blades are horizontally spreading and the lowermost sheaths are often pubescent. Ligules are short (up to 1 mm long) and there are also long auricles present at the collar. The inflorescence is an erect spike with overlapping spikelets attached in a spiral fashion, and 8-10 mm long with several florets. Glumes have convexly curved margins. Lemmas are awn-tipped or long-awned with awns up to 5 mm.
- Comments: Initially considered to be of value as a forage grass, quack grass’ tendency to invade has made it one of our nasty weeds. The long rhizomes can spread far and wide from an initial establishment site and the ability of even the smallest rhizome portion to be able to regenerate itself makes control is difficult. Reported to have some benefit for urinary problems, quack grass roots are known to secrete a toxic substance that inhibits seed germination, allowing it to out-compete other species on disturbed sites. Similar in general appearance to slender wheatgrass (Elymus trachycaulus) but rhizomatous. The native species, Elytrigia smithii or western wheatgrass, is scattered throughout the southwestern half of the state. It differs in having slightly longer spikelets with more slender glumes that taper evenly.
Additional species in Minnesota:
Copyright 2002, A.F. Cholewa, J.F. Bell Museum of Natural History, University of Minnesota / No portion of this guide may be duplicated without written permission of author.