2. Melampodium cinereum de Candolle in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 5: 518. 1836.
Melampodium cinereum var. hirtellum Stuessy; M. cinereum var. ramosissimum (de Candolle) A. Gray
Perennials or subshrubs, 10–20+ cm. Leaf blades linear-oblong to linear, 10–55 × 1–14 mm, lengths 3–10+ times widths, pinnately lobed, lobes 1–10, ultimate margins entire. Peduncles 1–7 cm. Outer phyllaries 5, connate 1/6–1/3+ their lengths, ovate, 3–7+ mm. Ray florets 7–13; corollas cream-white (sometimes purplish abaxially), laminae oblong-elliptic, 2–8+ × 1–3+ mm. Disc florets 25–50. Fruits 1.3–2.2 mm. 2n = 20, 40.
Flowering Jan–Jul. Open sites, sand, gravel, loam, or clay soils; 0–300 m; Tex.; Mexico (Coahuila, Nuevo León, Tamaulipas).
Along the interface of the distributions of Melampodium cinereum and M. leucanthum, some plants are intermediate for traits used to characterize the two species; perhaps the two should be treated as one.
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).