Agrostis gigantea Roth
Common Name: REDTOP
Coefficient of Conservatism: *
Coefficient of Wetness: -3
Wetness Index: FACW
Physiognomy: Ad P-Grass

A common grass throughout the state, in open to forested, wet to dry places, whether disturbed (roadsides, fields, etc.) or relatively undisturbed (wet meadows, shores, forests, dunes). Introduced from Europe, but collected in Michigan as early as 1838 in Jackson Co.

Agrostis gigantea is characteristically a distinctive large plant with a large, open, decidedly red inflorescence. Yet, plants growing in the shade, as in forests, may have greenish and often more delicate looking panicles, somewhat like those of A. stolonifera, which, however, usually grows in open situations, where A. gigantea develops its red color. The panicles of A. gigantea are normally at least 10 cm long. Depauperate specimens with smaller panicles may, if the panicle branches are ascending (as when young), resemble A. stolonifera, but usually can be distinguished by the reddish color, wider leaf blades, and of course the rhizome.


Alcona County
Alger County
Allegan County
Alpena County
Antrim County
Arenac County
Baraga County
Barry County
Bay County
Benzie County
Berrien County
Calhoun County
Cass County
Charlevoix County
    Including Beaver Island
Cheboygan County
Chippewa County
    Including Drummond Island
Clare County
Clinton County
Crawford County
Delta County
Dickinson County
Emmet County
Genesee County
Gladwin 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
Kalkaska County
Kent County
Keweenaw County
    Including Isle Royale
Lake County
Lapeer County
Leelanau County
    Including Fox Islands
    Including Manitou Islands
Lenawee County
Livingston County
Luce County
Mackinac County
    Including Bois Blanc, Mackinac, Round Islands
Macomb County
Marquette County
Mason County
Mecosta County
Menominee County
Midland County
Monroe County
Montmorency County
Muskegon County
Newaygo County
Oakland County
Oceana County
Ontonagon County
Oscoda County
Otsego County
Ottawa County
Presque Isle County
Roscommon County
Saginaw County
Sanilac County
Schoolcraft County
Shiawassee County
St. Clair County
St. Joseph County
Tuscola County
Van Buren County
Washtenaw County
Wayne County
Wexford County


MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 4, 2022.