''Oenothera californica'', known by the common name California evening primrose, is a species of flowering plant in the evening primrose family.

Distribution

The plant is native to regions of southern and western California, the

Southwestern United States The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural region of the United States that generally includes Arizona, New Mexico, and adjacent portions of California, Colorado, Ne ...

, and Baja California, Mexico. It is found in

desert A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...

and chaparral and woodlands habitats. Desert ecoregions include the Mojave Desert, Sonoran Desert, and Great Basin Desert. Chaparral and woodlands ecoregion locations include the southern California Coast Ranges, San Francisco Bay Area, Transverse Ranges, Channel Islands, and

Peninsular Ranges The Peninsular Ranges (also called the Lower California province) are a group of mountain ranges that stretch from Southern California to the southern tip of the Baja California peninsula; they are part of the North American Coast Ranges, which ...

Description

''Oenothera californica'' is a perennial herb producing a spreading or upright stem up to 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 three

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

of ''Oenothera californica'': * ''Oenothera californica'' ssp. ''avita'' — desert regions. * ''Oenothera californica'' ssp. ''californica'' — eastern and Southern California * ''Oenothera californica'' ssp. ''eurekensis'' — Eureka Dunes evening primrose.

Eureka Dunes evening primrose

''Oenothera californica'' ssp. ''eurekensis'', the rare Eureka Dunes evening primrose, is a federally listed

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

endemic to only a few occurrences in the Eureka Valley Sand Dunes in the Eureka Valley of Inyo County, eastern California. It grows alongside another local dune endemic, the endangered Eureka Valley dune grass (''

Swallenia ''Swallenia'' is a rare genus of plants in the grass family, found only in Death Valley National Park, California. The only known species is ''Swallenia alexandrae'', known by the common names Eureka dunegrass and Eureka Valley dune grass. This ...

alexandrae'').Center for Plant Conservation: ''Oenothera californica'' ssp. ''eurekensis''
/ref> It is sometimes listed as its

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

''Oenothera avita'' ssp. ''eurekensis''. The Eureka Valley Sand Dunes are within

Death Valley National Park Death Valley National Park is an American national park that straddles the California–Nevada border, east of the Sierra Nevada. The park boundaries include Death Valley, the northern section of Panamint Valley, the southern section of Eureka ...

. The main threat to the Eureka Dunes evening primrose was off-road vehicle use. That threat has been reduced and the plant's population has improved, but is still threatened by other human activities and an invasive species of tumbleweed,

Prickly Russian thistle ''Salsola tragus'', often known by its synonym is a species of flowering plant in the family Amaranthaceae. It is known by various common names such as prickly Russian thistle, windwitch, or common saltwort. It is widely known simply as tumblew ...

(''Kali tragus''). The United States Fish and Wildlife Service had recommended the plant be removed from the endangered species list.USFWS. The former subspecies ''Oenothera californica'' ssp. ''arizonica'' [], is now considered to be a separate species, ''Oenothera arizonica'' [].

References

External links

Calflora Database: ''Oenothera californica'' (California evening primrose)Jepson Manual eFlora (TJM2) treatment of ''Oenothera californica''U.C. CalPhotos gallery of ''Oenothera californica''
{{Taxonbar, from=Q5474684 californica Night-blooming plants Flora of California Flora of Arizona Flora of Baja California Flora of Nevada Flora of Utah Flora of the California desert regions Flora of the Great Basin Flora of the Sonoran Deserts Natural history of the California chaparral and woodlands Natural history of the Mojave Desert Natural history of the Peninsular Ranges Natural history of the Transverse Ranges Natural history of Inyo County, California Death Valley National Park IUCN Red List endangered species Taxa named by Sereno Watson Plants described in 1876