The species of Omalotheca have been placed in subg. Omalotheca (capitulescences of 1–10 heads, cypselae compressed-obovoid, and pappus bristles distinct and falling separately) and subg. Gamochaetiopsis Schultz-Bipontinus & F. W. Schultz (capitulescences of 10–100 heads, cypselae cylindric, and pappus bristles basally connate and falling together). In the flora, O. norvegica and O. sylvatica belong in subg. Gamochaetiopsis; O. supina is in subg. Omalotheca.