Taxonomy
Family: Asteraceae
Habitat
Sand dunes of lakes Michigan and Huron, and eastern Lake Superior.
Associates
Distribution
Ontario, MI, WI, IN, and historically in IL; restricted to the western Great Lakes. Has been reintroduced to IL.
Morphology
Monocarpic perennial to 1m, from a long taproot up to 6 feet long. Leaves white-tomentose, pinnately divided into very long, linear-oblong lobes; marginal spines mostly lacking. Flowers yellow-white to pinkish; bracts long-acuminate to weakly spiny, imbricate, slightly tomentose.
Notes
Flowers June and July
Wetland indicator: Upland
Dune thistle has declined due to the destruction of shoreline habitat along Lake Michigan and was extirpated from IL in the early 1900's. I took these photos while collecting data with Marlin Bowles (Morton Arboretum) and Tim Bell (Chicago State University). These populations are the result of a collaborative reintroduction effort begun in 1991 by the Morton Arboretum, Chicago State University, and the Chicago Botanic Garden.
References
Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of
Northeastern United States and Adjacent Canada. Second Ed.
The New York Botanical Garden. Bronx, NY
Swink, F. and G. Wilhelm. 1994. Plants of the Chicago Region.
Indiana Academy of Science. The Morton Arboretum. Lisle, Illinois.
USDA, NRCS. 2002. The PLANTS Database, Version 3.5 (http://plants.usda.gov).
National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
Michael Hough © 2004 |