Coefficient of Conservatism:
Coefficient of Wetness:
A. A. Reznicek
A Eurasian weed, locally established at edges of thickets and disturbed, young forests. It occurs especially along trails in northern forests, but in southern Michigan, may be a yard and garden weed. First collected in Washtenaw Co. by A. A. Reznicek in 1978. A 1927 collection from the University of Michigan Botanical Gardens notes "from Sweden" and may have been from cultivation.
This hybridizes with the native G. canadense to form G. ×catlingii J.-P. Bernard & R. Gauthier, with pale yellow petals (but much longer than those of G. virginianum). See the image of a G. ×catlingii flower with both parents under G. canadense. This hybrid has been confirmed from Calhoun and Washtenaw Cos., but is doubtless overlooked. A peculiarity of the hybrid is that the inflorescences may continue to grow, sometimes forming an elongated tangle.