Please try our next iteration of the Michigan Flora Online here. Beginning on February 1, 2023, will point to this new site.

The new site offers several benefits over the existing website, including real coordinate mapping, giving a clearer view of the density of documentation as well as more precision about plant distributions and their link to landforms. We will also have the ability to update species pages more regularly, both in terms of new collections and as more existing Michigan specimens are georeferenced. In addition, we have a better photo display, and offer indented keys.

Orobanche uniflora L.
Common Name: CANCER ROOT
Coefficient of Conservatism: 8
Coefficient of Wetness: 5
Wetness Index: UPL
Physiognomy: Nt P-Forb

Local, at edges of conifer thickets along dunes; even more local inland, in both dry sandy open areas and rich forests. Although this species has been reported throughout its range (covering most of the United States and southern Canada) from a diversity of hosts, Symphyotrichum and Solidago seem to be the only verified ones in Michigan.

Flowering pedicels are often 1–2 dm tall, although pedicels as short as 2 cm may bear a flower. The corollas are creamy white to bluish or purplish (at least in part) with two bright yellow lines (folds) extending from the sinuses of the lower lip into the throat. While not a “pretty” plant, it is interesting in its ghostly way and a crowded clump of 40 or 50 pedicels with flowers in full bloom can be impressive. More often, the pedicels are only solitary or a few blooming at any one time, although others may elongate and provide a long blooming season in early summer.


Arenac County
Berrien County
Calhoun County
Charlevoix County
    Only on Beaver Island
Cheboygan County
Chippewa County
    Including Drummond Island
Crawford County
Delta County
Emmet County
Genesee County
Gogebic County
Grand Traverse County
Houghton County
Ingham County
Jackson County
Kalamazoo County
Kent County
Leelanau County
    Including Fox Islands
    Including Manitou Islands
Lenawee County
Mackinac County
    Including Bois Blanc, Mackinac, Round Islands
Macomb County
Mecosta County
Monroe County
Oakland County
Ontonagon County
Presque Isle County
Washtenaw County


MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. January 30, 2023.