Summary. Woollyleaf bursage, [Ambrosia grayi (A. Nels.) Shinners], also known as bur ragweed, is a perennial noxious weed native to Kansas. It is a member of the Composite family and was referred to previously as Franceria tomentosa in the false ragweed family. Taxonomists were not able to distinguish between Ambrosia grayi and Franceria tomentosa and thus the accepted current Latin name is A…