The Comps of Mexico is a long-running series of systematic accounts of all the tribes and genera of the family Asteraceae. Chapter 19 in this treatment deals with the second half of the first part of the subtribe Helianthinae and covers genera Helianthus, Heliomeris, Hymenostephium, Iostephane, Lagascea, Sclerocarpus, Sidneya, Simsia, Tithonia, and Viguiera.