''Camissonia contorta'' is a species of

evening primrose ''Oenothera'' is a genus of about 145 species of herbaceous flowering plants native to the Americas. It is the type genus of the family Onagraceae. Common names include evening primrose, suncups, and sundrops. They are not closely related to ...

known by the common name plains evening primrose. It is an annual herb producing a slender, bending to curling red or green stem which is sometimes hairy. It is up to 30 centimeters long and erect or spreading out. The blue-green leaves are linear to very narrowly oval in shape and up to 3.5 centimeters long. The nodding

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

produces one or more small flowers. Each has bright yellow petals up to half a centimeter long, sometimes with small red dots near the bases. The fruit is a capsule about 3 centimeters long, containing 50 -100 tiny seeds. The range of ''Camissonia contorta'' includes

Transverse Range The Transverse Ranges are a group of mountain ranges of southern California, in the Pacific Coast Ranges physiographic region in North America. The Transverse Ranges begin at the southern end of the California Coast Ranges and lie within Santa B ...

in California at its southern range limit, north through Oregon, eastern Idaho, and eastern Washington in the United States, to

Vancouver Island Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian Provinces and territories of Canada, province of British Columbia. The island is in length, in width at its widest point, and in total area, while are o ...

in British Columbia, Canada at its extreme northern range limit. The species occurs in Köppen climates including BSk (cold semi-arid), Csa (hot summer Mediterranean), and Csb (warm summer Mediterranean). The species is a strict edaphic endemic of sandy soils. The soil can be derived from a diverse array of parent materials (rock types) that yield sandy textured soils, including

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

greywacke Greywacke or graywacke (German ''grauwacke'', signifying a grey, earthy rock) is a variety of sandstone generally characterized by its hardness, dark color, and poorly sorted angular grains of quartz, feldspar, and small rock fragments or lit ...

chert Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a prec ...

granite Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies undergro ...

, and

rhyolite Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...

(especially

volcanic ash Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcano, volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used t ...

and

pumice Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular vol ...

). The species favors (most common, abundant) moderately disturbed sandy soils, especially those worked by water (

alluvial deposits Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluv ...

along rivers) and wind (sand blow outs). There it occurs in sunny, open gaps between shrubs and trees. ''Camissonia contorta'' is listed as Critically Endangered (Canada rank S1) in British Columbia. In British Columbia, the species primarily occurs on Vancouver Island, immediately along the coastline from Metchosin, north through Victoria, to Sidney. The Koppen climate at Victoria is Csb. It's habitat on the coastline of Vancouver Island consists of semi-stable sandy flats and dunes no more than 15 m above sea level. These represent the northernmost known populations of ''Camissonia contorta'' and therefore, the extreme northern range limit of the species. Since this is the extreme northernmost range limit of the species and the only populations of the species known in Canada, it is classified as locally rare and endangered. Throughout the rest of the range of the species; however, it is locally common to abundant and reaches its greatest abundance in California.https://www.calflora.org/app/taxon?crn=1420 ''Camissonia contorta'' has no list status in the United States and is not regarded as rare.

References

External links

Jepson Manual TreatmentPhoto gallery

contorta ''Pinus contorta'', with the common names lodgepole pine and shore pine, and also known as twisted pine, and contorta pine, is a common tree in western North America. It is common near the ocean shore and in dry montane forests to the subalpine ...

Plants described in 1832 {{myrtales-stub