A purple color form of Pitcher's thistle

TitleA purple color form of Pitcher's thistle
Publication TypeJournal Article
Year of Publication2001
AuthorsVoss EG
JournalContributions from the University of Michigan Herbarium

Cirsium pitcheri (Compositae), a thistle endemic to the sandy shores and dunes of Lakes Michigan, Huron, and Superior, has hitherto been known to have heads only pale (white or cream) in color. A new form discovered at the north end of Lake Michigan has rich magenta corollas of a shade like that of the usual form of C. vulgare. This phenomenon is the reverse of the more usual discovery of a pale (or albino) form of a normally colored species.