Crocanthemum scoparium is a species in the Cistaceae (Rockrose) family which is endemic to California. There may be some taxonomic confusion about this species, and some sources include it in the genus Helianthemum. Its common names include Peak Rockrose and Peak Rushrose. There are two recognized varieties, both uncommon. This is a small perennial shrub bearing long, smooth stems and small flowers each with five bright yellow petals. It is found in dry, sandy areas in hills and low mountains primarily along the coast from the Bay Area southward, with a concentration in San Diego County. It should be noted that there are many non-native varieties of Cistus that are commonly available in nurseries; almost all are commonly called Rock Rose or Sun Rose.

Bisbee Peak Rush Rose (Helianthemum suffrutescens) is a rare native shrub that grows in northern, southern and central California. It tends to grow in dry and sandy slopes, at elevations from 0-1000 feet.

Croton californicus is a species of croton known by the common name California croton. This plant is a perennial or small shrub not exceeding a meter in height. The plant produces long oval-shaped leaves a few centimeters long and covered in a light-colored coat of hairs. This species is dioecious, with individual plants bearing either male (staminate) or female (pistillate) flowers, both only a few millimeters across. The staminate flowers are tiny cups filled with thready yellowish stamens and the pistillate flowers are the rounded, lobed immature fruits surrounded by tiny pointed sepals. This plant is native to California, Nevada, Utah, Arizona, and Baja California, where it grows in the deserts and along the coastline.

Turkey Mullein (Croton setigerus) is a squat plant with furry, feltlike, heart-shaped leaves that are pale gray green. The small green flowers are covered in soft bristles. It is about 8 inches high and has a rounded form.  As a result it is often planted in outdoor flower pots.

It takes full sun or part shade, requires very little water and is easy or moderately easy to grow. 

The foliage is toxic to animals. Birds, particularly doves and Wild Turkeys are attracted to the seeds. It hosts several butterfly and moth species.

Croton wigginsii is a species of croton known by the common name Wiggins' croton. This small gray-green shrub is native to the Sonoran Deserts of northern Mexico and Arizona, into the Colorado Desert in California where it is an inhabitant of sand dunes. This small gray-green shrub is native to the Sonoran Deserts of northern Mexico and Arizona, into the Colorado Desert in California where it is an inhabitant of sand dunes. Croton wigginsii is spreading shrub approaches a meter-3 feet in height. Its sparse foliage is made up of long oval-shaped leaves covered in a coating of white hairs. It is dioecious, with male plants bearing staminate flowers with thready stamens and female plants bearing pistillate flowers composed of the rounded immature fruits.

Cryptantha affinis is a flowering annual plant occurring in open areas of the coniferous forest. It is a member of the Boraginaceae family. It occurs at elevation ranges between 700 - 2900 m. Cryptantha species occur with other genera such as Clarkia, Hesperolinon, Lasthenia, Lupinus, Mimulus and Phacelia . Cryptantha affinis is native to California. Its distribution is from the Klamath, North coast, and Cascade Mountain Ranges. It also occurs in the Sierra Nevada, San Bernardino, and Warner Mountains and as far as Washington to Wyoming . Characteristics. C. affinis is an annual ranging from 5-40 cm in height. Stems are simple with little or no branching. Stems have stiff hairs lying parallel to the stem surface. Hairs also may curve upward slightly . Leaves are short and oblanceolate to oblong. Leaf size ranges from 1-4 cm. Leaf arrangement is opposite below and alternate above. Upper leave appear more oblong to lanceolate. Flowers are terminal and elongated when in fruit. Flowers are radial and can be open or dense in contact from side to side. Sepals are free. Flower color is generally white. Flowers are fused and lobed at the tip of the tube. Fruits are smooth ovate nutlets. Nutlets are in a group of four about 2 mm. Fruit shape is ovate. Fruits are smooth and shiny and black in color. Fruits are grooved and sometimes forked at the basal region. Most plants appear to be toxic due to their high levels of alkaloids and nitrates. Ecology. C. affinis physiology appears to be influenced by nutrients of Deer excretions. Increased photosynthesis and higher plant nitrogen levels have been observed in habitats frequented by Mule Deer, Antelope, and Elk. Higher nutrients appear to increase growth and reproduction in wet years. In dry years survival is increased by the shading of Cryptantha by the presence of large shrubs. Although shading increases survival in dry years, in wet years growth and reproduction seem to be reduced even when nutrient levels in the soil are high . Cryptantha species are dominant annuals in a wide range of habitats . In habitats where Cryptantha is a dominant species, fire intensity reduces its density .

Cryptantha clevelandii is a species of flowering plant in the borage family known by the common name Cleveland's cryptantha. It is native to coastal California and Baja California, where it grows in the chaparral and other habitat in the coastal hills. It is an annual herb growing a branching or unbranched stem up to 60 centimeters tall. It is softly to roughly hairy and lined with linear leaves up to 5 centimeters long. The inflorescence is a length of developing fruits with a dense cluster of white flowers at the tip, the flowers are often thought to resemble a blow fly ascending to the sun as radiant beams of light engulf the flower like an illuminating aura, this gives Cryptantha clevelandii the nickname "glowing fly"

Flaccid Cryptantha (Cryptantha flaccida) is a native annual herb that grows in northern, southern and central California. It tends to grow in open areas, at elevations from 0-6000 feet.

Cryptantha intermedia is a species of wildflower in the borage family known by several common names, including common cryptantha, Clearwater cryptantha, and nievitas. This plant is native to sagebrush scrub and chaparral plant communities, and woodlands and forests of western North America from British Columbia to Baja California. Cryptantha intermedia is an annual plant with a rough, hairy, branching stem reaching a maximum of half a meter in height. It grows from a mostly basal clump of hairy leaves one to several centimeters long. The erect stems are topped with one or more small flowers, each about a centimeter wide and bright white, sometimes with yellow coloration in the throat.

Cryptantha leiocarpa is a species of flowering plant in the borage family known by the common name coastal cryptantha. It is native to the coastline of Oregon and California where it grows in sandy areas such as beaches. This small annual herb grows an erect hairy, bristly branching stem to a maximum height near 30 centimeters. The stems droop and trail along the ground when they become long. The linear leaves are 1 to 3 centimeters long and have rough hairs. The plant bears small, tight clusters of white five-lobed flowers with yellow centers and tiny bristly sepals underneath.

Cryptantha micromeres is a species of flowering plant in the borage family known by the common name pygmyflower cryptantha. It is native to California and Baja California, where it grows in woodland and chaparral. Cryptantha micromeres is a hairy annual herb growing a branching stem to heights between 10 and 50 centimeters. The leaves are up to 4 centimeters long, variable in shape and covered in bristles. The inflorescence contains clusters of tiny bristly white flowers only a few millimeters wide.

Cryptantha microstachys is a species of flowering plant in the borage family known by the common name Tejon cryptantha. It is native to California and Baja California, where it grows in several types of habitat, including chaparral in the coastal and inland hills and mountains. It is an annual herb producing a branching or unbranched stem 10 to 50 centimeters tall which is coated in hairs and bristles. The hairy leaves are linear to oblong in shape and up to 4 centimeters long. The inflorescence is a length of bristly developing fruits tipped with open flowers with five-lobed white corollas just a few millimeters wide.

Cryptantha muricata is a species of flowering plant in the borage family known by the common name pointed cryptantha. It is native to California and adjacent parts of Arizona, Baja California, and Nevada, where it is known from many habitat types. It is an annual herb producing a branching 10 centimeters to one meter in height which is coated densely in rough and soft hairs. The leaves are linear in shape and no more than 4 centimeters long. They have hairs and bristles, some of which have bulbous bases. The flower cluster is a length of very hairy developing fruits tipped with a cluster of small five-lobed white flowers.

Cryptantha nevadensis is a species of wildflower in the borage family known by the common names Nevada catseye and Nevada forget-me-not. This small plant is native to the California, Utah, Arizona, and Baja California where it grows in sandy and rocky soils in varied habitats across the region. Like other cryptanthas it is a very hairy, bristly flowering herb with a curling inflorescence that resembles that of fiddlenecks. This is an annual plant rarely exceeding 1.5 feet in height. It is covered in long, white hairs and its tiny white flowers are about a quarter inch wide. The fruit is a bumpy nutlet.

Cryptantha pterocarya is a species of flowering plant in the borage family known by the common name wingnut cryptantha. It is native to the western United States where it grows in many types of habitat. It is an annual herb producing a stem with a few branches that reaches up to about 40 centimeters in maximum height. The leaves are linear to oblong in shape and up to 5 centimeters long. The plant herbage is very hairy to bristly, generally rough in texture. The inflorescence is a length of developing fruits tipped with one or more open flowers. The flower has a white five-lobed corolla. The fruit is a nutlet which is often, but not always, winged.

Torrey's Cryptantha (Cryptantha torreyana) is a native annual herb that grows in northern, southern and central California. It tends to grow in open places and slopes and , at elevations from 1500-7500 feet.

Cucurbita digitata is a species of flowering plant in the squash family known by the common names fingerleaf gourd and bitter squash. It is similar to Cucurbita californica, Cucurbita cordata, Cucurbita cylindrata, and Cucurbita palmata and all these species hybridize readily. These species form the only restricted xerophyte species group in the genus Cucurbita. Each member of this species group is native to the Southwestern United States and Northwestern Mexico where they are relatively uncommon. Each group member is found in hot, arid regions with low rainfall. They prefer soil that is loose, gravelly, and well-drained. C. digitata is native to northern Baja California at higher elevations, northern Sonora, Mexico, southern Arizona, and southwestern New Mexico. The juvenile leaves of C. cylindrata, C. cordata, C. digitata, and C. palmata show a high degree of similarity, but their mature leaves are visibly different, as are their root structures. C. palmata and C. digitata are sympatric, with C. palmata separating the ranges of C. digitata at the juncture of Baja California, California, and Arizona. C. digitata fruits are clear green mottle that turns yellow at maturity, striped, and round. It was first identified by Asa Gray in 1853. Cucurbita digitata is a hairy vining plant with sharply palmate leaves having five fingerlike lobes. It is quite similar in appearance to its close relative, the coyote gourd Cucurbita palmata, but the lobes of its leaves are usually more slender. It has curling yellow flowers up to 5 centimeters wide. The fruit is a dark green squash, rounded or nearly rounded, with mottling and distinct white stripes. The bitter fruit is very distasteful and generally not edible, although a few animals may hesitantly eat the flesh while trying to get at the seeds. Each white seed is about a centimeter long and at 35% protein and 50% fat is a nutritious food.

Cucurbita foetidissima (buffalo gourd, calabazilla, chilicote, coyote gourd, fetid gourd, Missouri gourd, stinking gourd, wild gourd, wild pumpkin) is a xerophytic tuberous plant found in the southwestern USA and northwestern Mexico. A member of the cucumber family, the fruit is consumed by humans and non-human animals both. The fruit can be eaten cooked like a squash when very young. As the fruit becomes fully mature, it is too bitter for humans to eat. At this stage, the fruit is used by natives for decorative purposes or in making musical instruments, particularly rattles. The seeds are the source of buffalo gourd oil. It grows fast (including a massive underground tuber) with little water, and some have proposed growing it for fuel or biofuel ethanol

Cucurbita palmata is a species of flowering plant in the squash family known by the common names coyote melon and coyote gourd. It is similar to Cucurbita californica, Cucurbita cordata, Cucurbita cylindrata, and Cucurbita digitata and all these species hybridize readily. It was first identified by Sereno Watson in 1876. These species form the only restricted xerophyte species group in the genus Cucurbita. Each member of this species group is native to the Southwestern United States and Northwestern Mexico where they are relatively uncommon. Each group member is found in hot, arid regions with low rainfall. They prefer soil that is loose, gravelly, and well-drained. C. palmata is native to northeastern Baja California, southeastern California, and southwestern Arizona to a point near the Colorado River. The juvenile leaves of C. cylindrata, C. cordata, C. digitata, and C. palmata show a high degree of similarity, but their mature leaves are visibly different, as are their root structures. C. palmata and C. digitata are sympatric, with C. palmata separating the ranges of C. digitata at the juncture of Baja California, California, and Arizona. C. palmata fruits are diffuse green mottle that turns yellow at maturity, striped, and round. Cucurbita palmata is a sprawling vine with rough, stiff-haired stems and leaves. The dark green, light-veined leaves are sharply palmate with usually five long triangular points. Cucurbita palmata is a sprawling vine with rough, stiff-haired stems and leaves. The dark green, light-veined leaves are sharply palmate with usually five long triangular points. The stiff, curling yellow flowers are 6 to 8 centimeters wide. The plant bears smooth spherical or oblate squash fruits 8 to 10 centimeters wide. The fruits may be bright yellow to dark green and may have white stripes. The fruit is distasteful and not edible.

Cupressus arizonica, the Arizona Cypress, is a species of cypress native to the southwest of North America, in the United States in Arizona, southwest New Mexico, southern California, and the Chisos Mountains of west Texas, and in Mexico in Coahuila, Chihuahua, Durango, Tamaulipas, Zacatecas and northern Baja California. In the wild, the species is often found in small, scattered populations, not necessarily in large forests. An example occurrence is within the Sierra Jurez and San Pedro Mrtir pine-oak forests of Mexico, where it is found along with Canyon Live Oak and California Fan Palm. It is a medium-sized evergreen tree with a conic to ovoid-conic crown. It grows to heights of 10-25 meter, and its trunk diameter reaches 0.5 meter. The foliage grows in dense sprays, varying from dull gray-green to bright waxy pale blue-green in color. The leaves are scale-like, 2-5 millimeter long, and produced on rounded (not flattened) shoots. The seed cones are globose to oblong, 15-33 millimeter long, with 6 or 8 (rarely 4 or 10) scales, green at first, maturing gray or gray-brown about 20-24 months after pollination. The cones remain closed for many years, only opening after the parent tree is killed in a wildfire, thereby allowing the seeds to colonize the bare ground exposed by the fire. The male cones are 3-5 millimeter long, and release pollen in February-March.

Cuscuta californica is a species of dodder known by the common names Chaparral dodder and California dodder. It is native to western North America. Cuscuta californica is a parasitic vine which climbs other plants and takes nutrition directly from them via a haustorium. The dodder resembles a pile of yellow-orange straw wrapped tightly around its host plant. It is mostly stem; the leaves are reduced to scales on the stem's surface, since they are not needed for photosynthesis while the dodder is obtaining nutrients from its host. It bears tiny white flowers which are only about 3 millimeters wide, and fruits which are even smaller.

Cuscuta campestris, with the common name large-seeded alfalfa dodder and prairie dodder, is a parasitic plant which belongs to the family Convolvulaceae. It was formerly classified in the family Cuscutaceae. It is native to central North America. It is a parasite of a wide range of herbaceous plants.

Cuscuta denticulata (desert dodder or small-toothed dodder) is a thin, yellow to orange, parasitic annual vine in the morning glory family (Convulvulaceae), native to the deserts of Southwestern America. Growth pattern. It is an annual plant that grows as a very thin orange-ish parasitic vine, with clumping twinings around the host stems. It parasitizes the host by sending small, short-lived rootlets (haustoria) into its tissues, from which it absorbs moisture and nutrients. Leaves and stems. Yellow to orange stems are without hairs, with minute scale-like leaves. Inflorescence and fruit. It blooms from May to October with tiny spikes of clusters of miniature white, 5-parted bell shaped flowers. Corolla lobes are bend back, with overlapping calyx lobes. Both calyx and corolla have fine teeth on their margins, hence the species name and common name. Fruits are conical capsules. Habitat and range. It grows up to 4,000 feet (1,200 m) in the Mojave Desert and Sonoran Desert into Baja California. It parasitizes plants of the creosote bush scrub and Joshua tree woodland communities, such as creosote bush (Larrea tridentata) and cheesebush (Ambrosia salsola).

Cuscuta pacifica is a species of dodder. Its common name is goldenthread. The plant is native to the coast of western North America from British Columbia to Baja California,. It is a halophyte, living in coastal salt marsh habitats, such as the San Francisco Bay. Cuscuta pacifica is a slender annual vine with yellowish thread-like stems that wrap tightly around other plants. The leaves are reduced to tiny scales, and it possesses no roots because it is a parasitic plant, like all Cuscuta, and taps nutrients from host plants with its haustoria. The salt marsh dodder produces flowers with bell-shaped, white glandular corollas with five pointed triangular lobes. It tends to parasitize Salicornia, but also may be found on other species such as Jaumea carnosa and Grindelia stricta. Varieties: The species includes two Varieties: Cuscuta pacifica var. pacifica is significantly more common, occurring throughout the species range. Cuscuta pacifica var. papillata is a very rare endemic of sand-dune habitats in Mendocino County. Previous treatments included this species as two varieties of a more broadly defined Cuscuta salina, but they were recently recognized to be a distinct species with clear habitat and host affinities and reproductively isolated from Cuscuta salina var. salina.

Cuscuta salina is a species of dodder known by the common name salt marsh dodder. It is native to western North America, where it lives in seasonal alkaline or saline habitats such as vernal pools and salt flats. It is a parasitic plant, wrapping itself around wetland vegetation and tapping them for nutrients with its haustoria. Cuscuta salina is a slender annual vine extending yellowish thready stems to wrap tightly around other plants. The leaves are rudimentary and scale-like. The dodder produces flowers with white glandular corollas. Each is bell-shaped with five pointed triangular lobes. Taxonomy. Previous treatments of the species divided it into three Varieties: In 2009, two of them were combined into a separate species called Cuscuta pacifica. The two species can easily be differentiated by habitat geography: the varieties of Cuscuta pacifica grow solely in coastal habitats while Cuscuta salina sensu stricto grows inland in alkaline or saline seasonally wet habitats such as vernal pools and salt flats, such as the margins of the Great Salt Lake.