Cirsium hillii (Canby) Fernald
Common Name: HILL'S THISTLE
Coefficient of Conservatism: 8
Coefficient of Wetness: 5
Wetness Index: UPL
Physiognomy: Nt P-Forb
Status: SC
Cirsium hillii M. R. Penskar

Dry open places, especially with jack pine and oak, but also prairie-like ground, thin soil over limestone (Drummond Island), and sandy banks. This species ranges from the Great Lakes region to Iowa, and was originally described from the south end of Lake Michigan. Collections from southern Michigan are almost all quite old (Oakland Co. 1849–1896; Washtenaw Co. in 1867; Jackson Co. 1894–1896; St. Clair Co. in 1904; Berrien Co. in 1932; and Kalamazoo Co. 1931–1939), and the species is now very rare in this part of the state. The rosettes of spiny leaves, the plants to bloom another year, are often conspicuous in grassy areas of jack pine savannas.

A number of recent authors treat this taxon as subsp. hillii (Canby) R. J. Moore & Frankton or var. hillii (Canby) B. Boivin of the more eastern and southern C. pumilum (Nutt.) Spreng. All reports of C. pumilum from Michigan refer to this taxon, whatever rank one prefers for it.

Locations

Alcona County
Berrien County
Cass County
Cheboygan County
Chippewa County
    Only on Drummond Island
Crawford County
Grand Traverse County
Hillsdale County
Iosco County
Jackson County
Kalamazoo County
Kalkaska County
Lake County
Menominee County
Montmorency County
Muskegon County
Newaygo County
Oakland County
Ogemaw County
Oscoda County
Otsego County
Presque Isle County
Roscommon County
St. Clair County
Washtenaw County

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 11, 2017. http://michiganflora.net/species.aspx?id=287.