Oenothera californica is a species of flowering plant in the evening primrose family known by the common name California evening primrose. It is native to parts of the southwestern United States and Baja California, where it can be found in deserts and woodlands.

Description

Oenothera californica is a perennial herb producing a spreading or upright stem up to 80 centimeters long. Young plants have a basal rosette of leaves, while older ones have leaves along the stem, lance-shaped to nearly oval in shape and up to 6 centimeters long. Flowers occur in the upper leaf axils, drooping in bud and becoming erect as they bloom. The four petals are white, fading pink, and may exceed 3 centimeters long.

Subspecies

There are currently considered to be three subspecies of Oenothera californica: ^[1]

• O. californica ssp. avita W.M.Klein 1962
• O. californica ssp. californica
• O. californica ssp. eurekensis (Munz & J.C.Roos) W.M.Klein 1962

Of these, the rare Eureka Dunes evening primrose (ssp. eurekensis), is a federally listed endangered species. It is sometimes listed as its synonym, Oenothera avita ssp. eurekensis. This subspecies is known from only a few occurrences in the Eureka Valley Sand Dunes in the Eureka Valley of Inyo County, California, where it grows alongside another dune endemic, the endangered Eureka Valley dune grass (Swallenia alexandrae).^[2]

The main threat to the Eureka Dunes evening primrose was off-road vehicle use. This threat has been eliminated and the plant's situation is much improved. The United States Fish and Wildlife Service has recommended the plant be removed from the endangered species list.^[3]

Oenothera californica ssp. arizonica (Munz) W.M. Klein 1962 is now considered to be a separate species: Oenothera arizonica (Munz) W.L.Wagner 1998.

See also

• Category: Flora of the California desert regions

References