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Carduus acanthoides L.
Common Name: PLUMELESS THISTLE
Coefficient of Conservatism: *
Coefficient of Wetness: 5
Wetness Index: UPL
Physiognomy: Ad B-Forb

Carduus acanthoides A. A. Reznicek

Roadsides, railroads, fields, farmyards, and other disturbed sites. First collected in 1920 in Washtenaw Co.

In areas of the Great Lakes region where both this and C. nutans are common and regularly co-occur, hybrids (C. ×orthocephalus Wallr.) are regular. These have not yet been seen in Michigan, but doubtless will be found in time.

The curly septate hairs along the veins of the underside of the leaf in this species are straight when fresh, though still visibly septate. The curling delelops on drying and is a herbarium feature.

 

Locations

Antrim County
Arenac County
Charlevoix County
    Only on Beaver Island
Cheboygan County
Emmet County
Kalamazoo County
Lenawee County
Mackinac County
Montmorency County
Oakland County
Washtenaw County
Wayne County

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. January 30, 2023. https://michiganflora.net/species.aspx?id=265.