Camissoniopsis bistorta is a species of flowering plant in the evening primrose family known by the common names southern suncup and California suncup. It is native to southern California and Baja California, where it grows in several types of plant community along the coast and in the coastal hills and mountain ranges. This is a hairy annual or perennial herb spreading from a basal rosette with stems reaching up to 80 centimeters long. Leaves are lance-shaped to narrowly arrowhead-shaped and sometimes toothed, and 1 to 12 centimeters in length. Toward the end of the spreading stems are nodding inflorescences of flowers, each flower with four bright yellow petals dotted with red at their bases. At the center are stamens and a protruding, nearly spherical stigma. The fruit is a straight or slightly coiled capsule up to 4 centimeters long.
Neoholmgrenia andina is a species of evening primrose known by the common name Blackfoot River evening primrose. It is native to western North America, including southern Canada and much of the western United States, where it is a plant of mountains, and sagebrush plateaus. It is a small annual herb growing a hairy, branching stem generally under 15 centimeters tall. The bunched leaves are widely lance-shaped and 1 to 3 centimeters long. The inflorescence bears one or more flowers with usually four tiny bright yellow petals. The fruit is a flat capsule up to a centimeter long.
Eremothera chamaenerioides is a species of evening primrose known by the common name long-capsule suncup. It is native to the southwestern United States and northern Mexico, where it grows especially in desert regions. It is an annual herb producing an erect, hairy, glandular stem which is reddish in color and up to half a meter tall. The leaves are lance-shaped or oval and up to 7 or 8 centimeters long. The nodding inflorescence produces several flowers, each with white petals a few millimeters long and drying to dull red. The fruit is a capsule 3 to 5 centimeters long.
Camissoniopsis hardhamiae is a species of evening primrose known by the common name Hardham's evening primrose. It is endemic to California, where it grows in the chaparral and woodland of San Luis Obispo and Monterey Counties. It is a robust annual herb producing a hairy stem up to about half a meter tall. The leaves are lance-shaped to narrowly oval and up to 12 centimeters long. The nodding inflorescence bears flowers with yellow petals each a few millimeters long. The fruit is a cylindrical capsule up to 2.5 centimeters long containing several dark-colored seeds.
Camissoniopsis intermedia is a species of evening primrose known by the common name intermediate suncup. It is native to California and Baja California, where it grows on the slopes of coastal and inland hills and mountains, especially in areas that have recently burned. It is an annual herb producing an erect, hairy stem up to about half a meter in height. Most of the leaves are located in a basal rosette at ground level and are oval to lance-shaped and up to 12 centimeters in length. The hairy, nodding inflorescence produces flowers with yellow petals just a few millimeters in length. The petals have one or two red dots at their bases. The fruit is a straight or coiling, wormlike capsule up to 2.5 centimeters long.
Tetrapteron palmeri is a species of evening primrose known by the common name Palmer evening primrose. It is native to the western United States from California to Idaho, where it grows in several habitat types, including desert and sagebrush. It is a roughly hairy annual herb growing in a low patch on the ground, generally with no stem. The leaves are widely lance-shaped and up to about 5 centimeters long, with a few small teeth along the edges. The nodding inflorescence produces flowers with yellow petals only 2 or 3 millimeters long each and a noticeable bulbous stigma tip which may be up to a centimeter wide. The fruit is a leathery capsule around half a centimeter long with small wings near the tip.
Camissonia pubens is a species of evening primrose known by the common name hairy suncup. It is native to the desert and steppe of western Nevada and eastern California. It is an annual herb covered in glandular hairs generally made up of one or more erect, slender stems up to a third of a meter tall. The leaves are up to about 4 centimeters long and are lance-shaped with wavy, toothed edges. The nodding inflorescence produces flowers with yellow petals each a few millimeters long and sometimes dotted with red near the bases. The fruit is a straight or coiling capsule up to 5 centimeters long.
Taraxia subacaulis is a species of evening primrose known by the common name diffuseflower evening primrose. It is native to the western United States, where it grows in several habitat types, especially in mountainous areas. It is a fleshy perennial herb growing from a taproot and usually lacking a stem. The leaves are lance-shaped to oval and up to 22 centimeters long and are borne on long petioles. The flower has yellow petals, each up to 1.5 centimeters long, and a large, bulbous stigma tip. The fruit is a leathery capsule 1 to 3 centimeters long.
Clarkia arcuata is a species of flowering plant in the evening primrose family known by the common name glandular clarkia. It is endemic to California, where it grows in the chaparral and woodlands of the foothills of the Sierra Nevada and southern Cascade Range. It is an annual herb producing a slender, erect stem often exceeding half a meter in height. The leaves are narrow, usually linear or lance-shaped, and up to 6 centimeters long. The inflorescence bears a few flowers, which dangle when they are buds and grow erect as they open. The sepals stay fused as the petals open and emerge from one side. They are coated in glandular hairs. The petals are up to 3 centimeters long, pink-lavender in color, sometimes with a reddish blotch at the base. They form a bowl-shaped corolla. There are 8 stamens and a protruding, four-chambered ovary. The fruit is an elongated capsule which may reach 3.5 centimeters long.
Clarkia lewisii is an uncommon species of flowering plant in the evening primrose family known by the common name Lewis' clarkia. It is endemic to California, where it is known from the hills and mountains of Monterey and San Benito Counties. It is an erect annual herb generally under half a meter in height. The lance-shaped leaves are a few centimeters long. The inflorescence bears opening flowers and closed, hanging flower buds. As the bud opens the pink or purple sepals stay fused as the petals bloom from one side. The fan-shaped petals are up to 3 centimeters long, pink to lavender with white and red coloration near the bases. There are 8 stamens and a protruding stigma.
Clarkia modesta is a species of flowering plant in the evening primrose family known by the common name Waltham Creek clarkia. It is endemic to California, where it is known from the woodlands of several of the central mountain ranges, including the North and Central Coast Ranges and the Sierra Nevada foothills. It is an erect annual herb often exceeding half a meter in height. The oval, linear, or lance-shaped leaves are 2 to 4 centimeters long. The inflorescence bears opening flowers and closed, hanging flower buds. The sepals remain fused as the petals bloom from one side. The petals are about a centimeter long and vary in shape from diamond to widely lance-shaped. They are pale to deep pink and generally dark-flecked or spotted.
Clarkia mosquinii is a rare species of flowering plant in the evening primrose family known by the common name Mosquin's clarkia. It is endemic to California, where it is known only from the northern Sierra Nevada foothills at the border between Butte and Plumas Counties. It was thought to be extinct until it was rediscovered in 1991. It is an erect annual herb often exceeding half a meter in height. The oval or lance-shaped leaves are 2 to 5 centimeters long. The inflorescence bears opening flowers below a series of clusters of closed, hanging flower buds. The sepals all separate as the flower blooms. The diamond-shaped petals are one to two centimeters long light to medium purple in color, and sometimes speckled with reddish purple.
Epilobium foliosum is a species of flowering plant in the evening primrose family known by the common names leafy willowherb and California willowherb. It is native to parts of western North America from British Columbia through California to Arizona, where it grows in many types of habitat, including disturbed areas.
Epilobium halleanum is a species of flowering plant in the evening primrose family known by the common name glandular willowherb. It is native to parts of western North America from British Columbia to New Mexico, where it grows in many types of habitat. It is an erect perennial herb growing up to about half a meter tall. The leaves are oval in shape low on the stem and narrower and somewhat lance-shaped higher, the longest about 4.5 centimeters long. The inflorescence is a raceme of glandular flowers, each with four notched white to pink petals a few millimeters long. The fruit is an elongated capsule up to 6 centimeters long.
Epilobium howellii is an uncommon species of flowering plant in the evening primrose family known by the common names Yuba Pass willowherb and subalpine fireweed. It is endemic to the High Sierra Nevada of California, where it is known from only about 20 occurrences.
Chamaenerion latifolium is a species of flowering plant in the evening primrose family known by the English common names dwarf fireweed and river beauty willowherb. It has a circumboreal distribution, appearing throughout the northern regions of the Northern Hemisphere, including subarctic and Arctic areas such as snowmelt-flooded gravel bars and talus, in a wide range of elevations. This is a perennial herb growing in clumps of leaves variable in size, shape, and texture above a woody caudex. The leaves are 1 to 10 centimeters long, lance-shaped to oval, pointed or rounded at the tips, and hairy to hairless and waxy. The inflorescence is a rough-haired raceme of nodding flowers with bright to deep pink, and occasionally white, petals up to 3 centimeters long. Behind the opened petals are pointed sepals. The fruit is an elongated capsule which may exceed 10 centimeters in length.
Epilobium oreganum is an uncommon species of flowering plant in the evening primrose family known by the common names Grants Pass willowherb and Oregon fireweed. It is native to southern Oregon and northern California, where it is historically known mostly from the Klamath Mountains. It is currently confirmed to exist only in Josephine County, Oregon, and Trinity County, California, where it grows in boggy areas on serpentine soils. It is a perennial herb growing up to a meter in height with thin, hairless stems. The red-veined leaves are oval to lance-shaped and up to 9 centimeters long. The inflorescence bears flowers with pink petals just over a centimeter long and a protruding pistil. The fruit is a hairy, glandular capsule up to 4.5 centimeters long.
Epilobium siskiyouense is a rare species of flowering plant in the evening primrose family known by the common names Siskiyou willowherb and Siskiyou fireweed.
Oenothera glazioviana is a species of flowering plant in the evening primrose family known by the common names large-flowered evening-primrose and redsepal evening primrose.
Oenothera harringtonii is a species of flowering plant in the evening primrose family known by the common names Arkansas Valley evening primrose and Colorado Springs evening primrose. It is endemic to the state of Colorado in the United States.
