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Common Name:
SWAMP THISTLE
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Coefficient of Conservatism:
6
Coefficient of Wetness:
-5
Wetness Index:
OBL
Physiognomy:
Nt B-Forb
L. N. May
Calcareous shores, sedge meadows, fens; swamps of cedar, tamarack, and other conifers (less often hardwoods); moist ground along rivers and streams.
The flowers are a deep rose-purple; combined with the relatively unarmed stem, they make this species unusually attractive as thistles go. White-flowered plants [f. lactiflorum Fernald] have been collected in Keweenaw, Livingston, and Oakland Cos. The phyllaries are less acute (even obtuse or blunt) compared with our other small-headed thistles (C. arvense and C. palustre, both introduced, weedy species), which have pale pink-purple flowers. Occasionally the leaves are lightly tomentose beneath, but not enough so to hide completely the green surface of the blade.
Locations
Alcona County
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Allegan County
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Alpena County
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Antrim County
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Arenac County
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Baraga County
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Barry County
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Bay County
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Benzie County
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Berrien County
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Calhoun County
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Cass County
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Charlevoix County
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Cheboygan County
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Chippewa County
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Including Drummond Island
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Clare County
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Clinton County
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Crawford County
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Delta County
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Dickinson County
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Emmet County
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Gogebic County
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Grand Traverse County
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Gratiot County
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Hillsdale County
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Houghton County
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Huron County
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Ingham County
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Iosco County
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Iron County
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Jackson County
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Kalamazoo County
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Kalkaska County
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Kent County
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Keweenaw County
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Including Isle Royale
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Lake County
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Lapeer County
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Leelanau County
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Lenawee County
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Livingston County
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Luce County
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Mackinac County
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Macomb County
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Marquette County
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Mason County
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Mecosta County
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Midland County
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Missaukee County
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Monroe County
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Montcalm County
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Montmorency County
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Muskegon County
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Newaygo County
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Oakland County
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Ogemaw County
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Ontonagon County
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Oscoda County
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Ottawa County
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Presque Isle County
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Roscommon County
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Schoolcraft County
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St. Clair County
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St. Joseph County
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Tuscola County
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Washtenaw County
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Wayne County
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Citation:
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. January 29, 2023. https://michiganflora.net/species.aspx?id=288.