Santa Fe Botanical Garden

Common name: tufted evening primrose, stemless evening primrose, fragrant evening primrose

Family: Onagraceae (Evening Primrose)

Synonym: Oenothera caespitosa

Distribution: Western North America

Habitat: Rocky hillsides and bluffs, open forests and woodlands, arroyos, scrublands

Hardiness: USDA Zone 5 (-20 to -10 °F)

Life form: Deciduous perennial

Occurrence in New Mexico: New Mexico native plant

Growing Conditions: The native range of Oenothera cespitosa includes much of western North America, from Saskatchewan and Alberta west through the Dakotas, Montana, Idaho and Washington, and south to California, Arizona, New Mexico, and northern Mexico. The species also grows in the northeastern states, but it has likely been introduced there. It is a very common perennial in dry lower to middle elevation plains and open hillsides, at elevations from 3,000-7,500 feet. It grows in a wide range of habitats, including scrublands, piñon-juniper woodlands, rocky slopes and bluffs, arroyos and alluvial deposits. It occasionally grows as high as timberline in montane conifer forests. Loose colonies of plants are sometimes formed around rodent holes and harvester ant mounds. Plants grow from a stout taproot, and colonies form from spreading lateral roots that emerge from the taproot.

Description: Tufted evening primrose is a low-growing perennial that grows up to 8 inches tall and 2-3 feet wide from a woody base and stout taproot. There are usually no distinct stems, but new shoots may emerge from lateral roots. The oblong or narrowly elliptical leaves, 1-10 inches long and ⅕-1½ inch wide, form a basal rosette. They have long stalks (petioles) and irregular teeth or lobes, and are especially hairy along the margins. Fragrant, showy white flowers, disproportionately large compared to the rest of the plant, emerge singly from among the leaves. They have 4 heart-shaped petals that open in late afternoon, fade to pink, and wilt the next day. The base of the flower is an enlarged tube (hypanthium) that contains the ovary. There are 8 stamens with large anthers and the 4-parted stigma stands well above them. There are several intergrading subspecies.