Oenothera andina Nuttall in J. Torrey and A. Gray, Fl. N. Amer. 1: 512. 1840; Camissonia andina (Nuttall) P. H. Raven; Holmgrenia andina (Nuttall) W. L. Wagner & Hoch; O. andina var. anomala M. Peck; Sphaerostigma andinum (Nuttall) Walpers

Herbs finely strigillose, more densely so distally, especially on ovary. Stems erect to ascending, capillary, 1–15 cm. Leaves linear to linear-oblanceolate. 1–3 × 0.1–0.3 cm. Flowers opening near sunrise; floral tube 0.8–2 mm; sepals 0.8–2.5 mm; petals 0.8–2.3 mm; episepalous filaments 0.5–2.2 mm, epipetalous filaments 0.1–0.5 mm, sometimes epipetalous stamens absent, anthers of longer stamens 0.2–0.5 mm, those of shorter ones 0.1–0.5 mm; style 1.7–3 mm, usually glabrous, rarely sparsely pubescent near base, stigma 0.4–0.6 mm diam., surrounded by anthers at anthesis. Capsules ascending, strongly flattened from unequal width of valves, (5–)8–10 × 1–1.3 mm. Seeds 0.7–1.3 × 0.3–0.4 mm. 2n = 28, 42.

Flowering May–Jul. Open places, clay or sandy soil, swales or drying meadows, playa bottoms, gravelly slopes, sagebrush scrub, pinyon-juniper woodlands; 500–2000 m; Alta., B.C.; Calif., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.

Some individuals of Neoholmgrenia andina have 3-merous flowers and some have stamens reduced to one whorl of four; both character states are possibly related to its predominant autogamous, and sometimes cleistogamous, habit (P. H. Raven 1969).