Silphium laciniatum L.
Common Name: COMPASS PLANT

Coefficient of Conservatism: 9
Coefficient of Wetness: 5
Wetness Index: UPL
Physiognomy: Nt P-Forb
Status: T

Like S. perfoliatum, mostly to the south and west of Michigan. At least in part probably adventive along railroads (e.g., Jackson, St. Clair, Washtenaw, and Wayne Cos.), although railroad rights-of-way and depauperate prairies are indeed about all we have left of its proper habitat.

The common name refers to the tendency of the lower leaves to orient themselves vertically in a north-south direction when exposed to full sun (thus escaping the full radiation that a horizontal leaf would receive).

Locations

Berrien County
Cass County
Delta County
Jackson County
Kalamazoo County
Kent County
Lenawee County
Menominee County
St. Clair County
Washtenaw County
Wayne County

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. September 1, 2014. http://michiganflora.net/species.aspx?id=446.