These common weedy plants are considered to have a largely western origin in prairies of the Great Plains, but they appear to have spread east after forest clearance (F, Cr). There has probably been some intergradation with typical hirta, and now there is frequent confusion by botanists; see also notes under bicolor. These closely related taxa in the "hirta complex" are sometimes confused with the "fulgida complex" but differ as follows (F, Cr, Y): plants usually taprooted annuals or biennials (versus perennial, often with stoloniferous offsets); stems and leaves more or less densely hairy with relatively long spreading whitish hairs (versus densely to sparsely hairy, usually without long spreading whitish hairs); cauline leaves often more broad-based, with winged petiole or subsessile to clasping; apices of pales densely fringed with spreading bristly whitish hairs (versus glabrous or with short pectinate hairs); stigma lobes elongated and more or less sharply pointed (versus short and rounded to bluntly pointed); pappus absent (versus present).