Pictured from left to right: Elymus canadensis and Elymus hystrix (2 photos)
This genus is characterized by long spikes with usually 2 or 3 sessile spikelets per node. Spikelets have several florets and the glumes tend to be narrow and turned toward the front of the spikelet. Leaves are flat and broad and many species have tiny finger-like projections ("auricles") on the front side of the collar area, at the top of the sheath margins. Plants are either cespitose or rhizomatous.
There are 10 species in MN; 9 are native.
Elymus canadensis (eh' lih muss can na den' sis)
- Synonyms: None
- Common names: Canada wild-rye, nodding wild-rye; Lakota: pteya hota
- Origin and habitat: Native; moist habitats, often along streams.
- Identifying characters: A short-lived perennial bunchgrass up to 15 dm tall. Leaves often have a hardened collar area and very tiny ligules (usually less than 1 mm long); obvious auricles are present. Inflorescences usually are slightly nodding, and the spikelets are paired at each node (occasionally the lower nodes with 3); spikelets overlap one another. Glumes widen above the base and lemmas taper into an awn that is much longer than the body of the lemma. The awns become curved upon drying.
- Comments: This is one of the few natives species that is a cool-season grass, doing most of its growth during spring and/or fall. It has good germination and is very winter-hardy (as most cool-season grasses would have to be). It can be a good forage grass if it is harvested early as it is susceptible to the ergot fungus.
Elymus hystrix (eh' lih muss hiss' trix)
- Synonyms: Hystrix patula
- Common names: bottlebrush grass
- Origin and habitat: Native; moist hardwood or mixed hardwood/coniferous forests
- Identifying characters: Generally occurring as isolated individuals with only a few stems clustered together. Leaf blades often have scattered hairs on the upper surface, with tiny ligules (less than 1 mm long); obvious auricles are present. The distinctive inflorescences are erect or slightly nodding spikes. Spikelets are paired at each node, nearly perpendicular to the main stem at full maturity, with 2-4 flowers each. Glumes are bristle- or awn-like (rarely absent) and shorter than the lemmas, whose apices taper into straight awns, 1-4 cm long.
- Comments: This is a rather striking and distinctive forest grass. When clustered together the plants can be quite attractive in the garden. The inflorescences are sometimes picked for dried bouquets (picking must occur just after flowering or they will shatter upon drying).
Elymus trachycaulus (eh' lih muss tray key kaw' lus)
- Synonyms: Agropyron trachycaulum, A. caninum
- Common names: slender wheatgrass
- Origin and habitat: Native; various habitats but especially dry, rocky or gravelly areas
- Identifying characters: A cespitose perennial with leaf blades slightly keeled near the collar area and with tiny ligules (up to 1 mm long). The inflorescence is a narrow erect spike 4-15 cm long with spikelets solitary at the nodes but overlapping. Glumes are acute or tapering to a short awn and the lemmas are awnless or with a short awn 1-3 cm long, and occasionally are hairy on the margins.
- Comments: This species differs from other Elymus in our area in that there is generally only one spikelet at each node. Its overall appearance can vary greatly. Seedling establishment is very good and the plants generally are tolerant of alkaline conditions.
Elymus virginicus (eh' lih muss vir jih' nih cuss)
- Synonyms: None
- Common names: Virginia wild-rye, terrell grass
- Origin and habitat: Native; occurring in various habitats, most often moist woods
- Identifying characters: The outer margin of the leaf sheath is often ciliate and the collar area is generally hardened. Ligules are minute (up to 0.5 mm long) and auricles are present. Inflorescences are rigid erect spikes, 4-12 cm long. Glumes are similar to the lemmas but narrower and with a hardened bowed-out base and an awn-tipped apex. Lemmas usually are awned, with the awn 0.5-3.5 cm long (the short-awned varieties are called var. submuticus).
- Comments: Similar in appearance to Canada wild-rye (E. canadensis), Virginia wild-rye has a stiffer, more erect inflorescence. The glumes have a bowed-out base and remain straight even after drying. Its appearance (particularly the glumes and lemma characters) can also vary depending on subtleties of the habitat.
Additional Species in Minnesota:
E. x macounii
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.