Sonchus arvensis L.
Common Name: FIELD SOW-THISTLE, PERENNIAL SOW-THISTLE
Synonym: Sonchus uliginosus
Coefficient of Conservatism: *
Coefficient of Wetness: 3
Wetness Index: FACU
Physiognomy: Ad P-Forb

Roadsides, railroads; meadows, shores, disturbed wetlands and dikes; fields, weedy among crops and in gardens; disturbed sites, including fill, parking lots, dumps. Collected at Lansing (Ingham Co.) as long ago as 1867, but not gathered again until the 1890’s in several counties (Bay, St. Clair, Tuscola, Wayne); now all too common throughout the state.

In S. arvensis subsp. arvensis, the involucres and pedicels bear numerous stiff hairs tipped with dark glands. More common in Michigan is subsp. uliginosus (M. Bieb.) Nyman (var. glabrescens Günther, Grab. & Wimmer), which lacks the glandular hairs and may average slightly smaller involucres.

Locations

Alcona County
Alger County
Allegan County
Alpena County
Antrim County
Arenac County
    Including Charity Island
Baraga County
Barry County
Bay County
Benzie County
Berrien County
Calhoun County
Charlevoix County
    Including Beaver Island
Cheboygan County
Chippewa County
    Including Drummond Island
Clinton County
Crawford County
Delta County
Dickinson County
Eaton County
Emmet County
Gladwin County
Gogebic County
Grand Traverse County
Gratiot County
Hillsdale County
Houghton County
Huron County
Ingham County
Iosco County
Iron County
Isabella County
Kalamazoo County
Kent County
Keweenaw County
    Including Isle Royale
Lapeer County
Leelanau County
    Including Fox Islands
    Including Manitou Islands
Lenawee County
Livingston County
Mackinac County
    Including Bois Blanc, Mackinac, Round Islands
Macomb County
Marquette County
Mason County
Mecosta County
Menominee County
Missaukee County
Monroe County
Montcalm County
Montmorency County
Muskegon County
Newaygo County
Oakland County
Ontonagon County
Oscoda County
Ottawa County
Presque Isle County
Roscommon County
Saginaw County
Sanilac County
Schoolcraft County
Shiawassee County
St. Clair County
Tuscola 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 17, 2017. http://michiganflora.net/species.aspx?id=473.