Plants of Melampodium cinereum with leaf blades linear-oblong and basally strigose with hairs 0.3–0.6 mm have been treated as var. cinereum, plants with leaf blades linear-oblong and basally strigose with hairs 0.6–1.5 mm as var. hirtellum, and plants with leaf blades linear and basally strigose with hairs 0.3–0.6 mm as var. ramosissimum (T. F. Stuessy 1972).