Pale evening-primrose is an upright perennial wildflower, with several simple to many several-branched stems to 50 cm tall. The outer covering of the stems is whitish, and exfoliates. The herbage varies from glabrous to densely covered with short hairs or longer, stiffer and sharp hairs closely appressed to the stems or leaves. The leaves are very numerous, primarily on the stems. Individual leaves are linear to linear-oblanceolate, from 2 to 6 cm in length and 5 to 10 mm wide. The leaf margins are variable, from entire to serrate, or with several prominent basal tooth-like lobes. The leaf blades narrow gradually to petioles 5 to 15 mm long.
The fragrant flowers are in leafy spikes. The buds nod. The floral tube is 1.5-3.5 cm long. The connate sepals are 1 to 2.5 cm in length, and turned to one side in flower. The four petals are obovate and rounded in shape, and are 15 to 30 mm in length. The petals are white, aging to pink. The stamens are about equal in length to the petals with anthers 4-9 mm long. The style is exserted about 1-2.2 cm beyond the floral tube and is just longer than the stamens. The fruit is a capsule from 1.5-5 cm long and 1.5-2.5 mm thick. The capsule is spreading to ascending and may be straight, arched or coiled.
Plants in the Pacific Northwest are variety pallida.
Pale evening-primrose is found primarily on sand dunes, but may occasionally be observed in gravelly soils from the lowlands up to 2500 meters in the mountains. It may also be found along roadsides and other disturbed areas.
Pale evening-primrose is found throughout eastern Oregon and Washington eastward to Idaho, and hence south to New Mexico and Arizona.
