Oenothera chamaenerioides A. Gray, Smithsonian Contr. Knowl. 5(6): 58. 1853; Camissonia chamaenerioides (A. Gray) P. H. Raven; O. erythra (Davidson) J. F. Macbride; Sphaerostigma chamaenerioides (A. Gray) Small; S. erythrum Davidson

Herbs glandular puberulent and sparsely strigillose distally, especially in inflorescence. Stems usually well branched from base, 8–50 cm, flowering only distally. Leaves cauline, with lower ones clustered near base, (0.7–)2–8(–10) × 0.1–2.5 cm; petiole 0.1–3.5 cm; blade very narrowly elliptic to narrowly elliptic, margins entire or sparsely denticulate. Inflorescences nodding. Flowers opening at sunset; floral tube 1.5–3 mm, villous in proximal 1/2 inside; sepals 1.5–2.5 mm; petals white, fading pinkish, 1.8–3 mm; episepalous filaments 0.7–1.5 mm, epipetalous filaments slightly shorter, anthers 0.5–1.1 mm; style 2.3–4.5 mm, villous prox­imally, stigma 0.7–1 mm diam., surrounded by anthers at anthesis. Capsules narrowly cylindrical throughout, spreading, straight, terete, 35–60 × 0.7–1 mm, regu­larly but tardily dehiscent. Seeds monomorphic, gray, 0.9–1 × 0.3–0.4 mm, finely reticulate. 2n = 14.

Flowering (Jan–)Feb–Jun. Sandy desert slopes and flats; -50–1700 m; Ariz., Calif., Nev., N.Mex., Tex., Utah; Mexico (Baja California, Sonora).

Eremothera chamaenerioides occurs in sub-Mogollon Arizona, southeastern California, southern Nevada, southern New Mexico, trans-Pecos Texas, and Kane, Millard, Tooele, and Washington counties, Utah. P. H. Raven (1969) determined Eremothera chamaenerioides to be self-compatible and autogamous.