Long-Bracted Tickseed Sunflower (Bidens polylepis S.F.Blake)

Also known as Ozark beggar-ticks, Midwestern tickseed sunflower; also classified as Bidens aristosa var. polylepis.

Some authorities, including USDA PLANTS and BONAP, lump this in with bearded beggarticks (Bidens aristosa) and do not recognize any sub-taxa. A few authorities treat this as a variety of that species, var. polylepis. We follow POWO's scheme in separating them, which is also used by Go Botany, FSUS, and others. However we note that, for some unknown reason, POWO does not list the name Bidens aristosa var. polylepis, even though it is in use, and furthermore, POWO lists Bidens aristosa var. retrorsa (Sherff) Wunderlin as a synonym of this species, which probably reflects that type specimen belonging to this taxon. However this synonymy, even if technically correct as referred to the type specimen, is confusing because among authorities that separate these taxa into varieties, that name usually refers to B. aristosa under our scheme.