Eureka Dunes evening primrose

Oenothera deltoides Torrey & Frémont subsp. eurekensis Munz & J. C. Roos, Aliso 3: 118, fig. 7. 1955; O californica (S. Watson) S. Watson subsp. eurekensis (Munz & J. C. Roos) W. M. Klein

Herbs perennial, densely strig­illose and villous; with deep-seated, fleshy underground parts from underground horizontal rootstocks. Stems sprawling to decumbent, sometimes new rosettes forming at stem apex when becoming buried in drifting sand, 15–60 cm. Leaves: blade rhombic-ovate to oblanceolate, margins entire or weakly dentate. Flowers: floral tube 25–30 mm; sepals 15–25 mm; petals 20–30 mm. Capsules 30–70 mm. 2n = 14.

Flowering (Mar)Jun–Jul(Sep). Sand dunes; of conservation concern; 900–1200 m; Calif.

Subspecies eurekensis is known from three main areas within the Eureka Dunes system, Inyo County. It is federally listed as endangered and is in the Center for Plant Conservation’s National Collection of Endangered Plants.