Heterotheca camporum var. glandulissimum Semple was almost unknown before 1900, but whose range expanded rapidly since then (Semple 1983).  It is adapted to glades and disturbed areas originally in central Tennessee and maybe northern Alabama, but has become weedy expanding along Interstate Hwys northward and eastward.  It has also been introduced int southwestern Missouri and northern Arkansas, probably as a result of tourist traffic between Nashville, TN and the country music centers in the western area.  It is now being offered for sale in the horticulture trade and has even established itself in a locations in western Europe.  It is the only taxon in Heterotheca that transplants well and has been grow in a garden in Waterloo for 25 years, but has not spread.  Introduction of multiple individuals could lead to seed set and the plants becoming potentially invasive.