Melampodium cinereum

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).