Elymus trachycaulus (Link) Gould
Common Name: SLENDER WHEATGRASS
Synonym: Agropyron trachycaulum
Coefficient of Conservatism: 8
Coefficient of Wetness: 3
Wetness Index: FACU
Physiognomy: Nt P-Grass

Elymus trachycaulus B. S. Walters

Agropyron trachycaulum of Michigan Flora.

Widespread, but perhaps most often in dry or rocky forests and savannas (oak, jack pine, hickory), sand barrens, shores, and dunes; also recorded for fens and tamarack swamps; sometimes along roadsides and in other disturbed places.

All our plants are apparently referable to the highly variable subsp. trachycaulus (Barkworth, Campbell & Salomon 2007).

Fortunately, this extremely variable species can usually be easily recognized, if young by the short anthers, and if old by the very readily disintegrating spikelets (as also Pseudoroegneria spicata). In addition, the rachilla is nearly always strongly villous with fine, flexible hairs, especially in those forms most likely to be otherwise confused with other species (none of which have villous rachillas).

Occasionally some nodes of the spike may bear 3 spikelets, but such plants have only 1 spikelet at most nodes; they may also be distinguished from E. glaucus, which they resemble, by the villous rachilla, the generally narrower leaf blades, and the wider glumes.

Certain plants from the Huron Mountain area, Marquette Co., and elsewhere on the Lake Superior shore appear to be hybrids of E. trachycaulus and E. repens. The plants have the rhizomatous habit and long anthers (4–5 mm) of the latter species; the rachilla is glabrous or villous, disarticulating as in E. trachycaulus, and the glumes and lemmas are prominently awned.

Locations

Alcona County
Alger County
Allegan County
Alpena County
Antrim County
Arenac County
Baraga County
Barry County
Bay County
Benzie County
Berrien County
Calhoun County
Charlevoix County
    Including Beaver Island
Cheboygan County
Chippewa County
    Including Drummond Island
Clare County
Clinton County
Crawford County
Delta County
Emmet County
Gogebic County
Grand Traverse County
Gratiot County
Hillsdale County
Houghton County
Huron County
Ingham County
Ionia County
Iosco County
Iron County
Jackson County
Kalamazoo County
Kent County
Keweenaw County
    Including Isle Royale
Lake County
Leelanau County
    Only on Fox Islands
Lenawee County
Livingston County
Luce County
Mackinac County
    Including Bois Blanc, Mackinac, Round Islands
Macomb County
Manistee County
Marquette County
Menominee County
Midland County
Missaukee County
Montmorency County
Muskegon County
Newaygo County
Oakland County
Ontonagon County
Presque Isle County
Roscommon County
Schoolcraft County
St. Clair County
Washtenaw County
Wayne County

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 16, 2017. http://www.michiganflora.net/species.aspx?id=2103.