Western red cedar (Thuja plicata), also Western redcedar, is a species of Thuja, an evergreen coniferous tree in the cypress family Cupressaceae. In the American horticultural trade, it is also known as the Giant Arborvitae, Arborvitae being another name for its genus. Western red cedar is the Provincial tree of British Columbia, and has extensive applications for the indigenous First Nations of the Pacific Northwest. The western red cedar is not actually a cedar (Cedrus), but belongs in the Cupressaceae family, along with cypresses. It is known by many names, Pacific red cedar, British Columbia cedar, canoe cedar, giant cedar, or just red cedar. Plicata, the species name, derives from a Greek word meaning "folded in plaits", a references to the pattern of its small leaves. It is one of two arborvitaes (Thuja) native to North America. Arborvitae comes from the Latin for "tree of life". Coincidentally, native Americans of the West coast also address the cedar as "long life maker".

Western red cedar is valued for many industrial uses, including roof shingles, construction and cedar chests. It is allergenic, can cause asthma, and construction workers are advised to limit exposure.

Left to itself, it will grow above 200 '. It can be pruned and trained to become a thick 6' tall hedge.

Thymophylla pentachaeta, also known as golden dyssodia or dogweed, is a perennial or subshrub in the Asteraceae family. The species is native to the southwestern United States and Mexico Four varieties are recognised:

Fiveneedle Pricklyleaf (Thymophylla pentachaeta var. belenidium) is a clumping yellow-flowered perennial in the Asteraceae or sunflower family. It blooms spring to fall with masses of yellow flowers above feathery aromatic foliage. In the wild, it is found in the San Jacinto Mountains and Sonoran Desert, as well as west as far as Texas.

This is an excellent small plant for hot sunny areas. It likes fast-draining soil. It will reseed easily and attracts pollinators.

Thysanocarpus conchuliferus is a rare species of flowering plant in the mustard family known by the common name Santa Cruz Island fringepod. It is endemic to Santa Cruz Island, one of the Channel Islands of California, where has been recently observed at only one location; some years it is totally absent. It is a federally listed endangered species of the United States, and a review by the US Fish & Wildlife Service in 2009 suggests it should remain on the list. The plant's habitat is the coastal scrub on the rocky, windblown slopes and canyons of its single island.

Thysanocarpus curvipes is a species of flowering plant in the mustard family known by the common names sand fringepod and lacepod. It is native to western North America from British Columbia through the western United States to Baja California, where it grows in many types of habitat. It is a common plant in much of its range. It is variable in appearance. It is an annual herb producing a branching or unbranched stem 10 to 80 centimeters tall. The leaves are mostly lance-shaped but variable. The lower ones are sometimes borne on petioles and the upper ones may clasp the stem at their bases. They may be smooth-edged, toothed, or lobed. The inflorescence is a raceme of flowers with four white or purple-tinged petals and purple sepals. The fruit is a flattened, rounded or oval disclike capsule with a thin wing around the edge. The fruit is under a centimeter long and the wing is variable in appearance, flat or wavy, sometimes perforated.

Thysanocarpus laciniatus is a species of flowering plant in the mustard family known by the common name mountain fringepod. It is native to California and Baja California, where it grows in many types of habitat. It is a common plant in much of its range. It is an annual herb producing a slender, branching or unbranched stem 10 to 60 centimeters tall. It is somewhat waxy in texture and generally lacks hairs. The leaves are linear to lance-shaped and smooth-edged or toothed. They measure up to 4 centimeters in length. The inflorescence is a raceme of small whitish or purplish flowers. The fruit is a flattened, rounded or oval disclike capsule with a thin wing around the edge.

Thysanocarpus radians is a species of flowering plant in the mustard family known by the common name ribbed fringepod. It is native to northern and central California and Oregon, where it grows in moist meadows, fields, hillsides, and other habitat. It is an annual herb growing up to 50 or 60 centimeters tall. The leaves are wavy-edged or lobed, the basal ones up to 5 centimeters long and ephemeral, and the upper ones with bases clasping the stem. The inflorescence is a long, open raceme of small whitish or purplish flowers. The fruit is a flattened, rounded, disclike capsule which hangs from its pedicel. It measures up to a centimeter long and is hairless to quite hairy in texture. The flat wing lining the edge of the disc is ribbed with rays like the spokes of a wheel, a characteristic making it easily distinguished from other Thysanocarpus when it is in fruit.

Toxicodendron diversilobum, commonly named poison oak, Pacific poison oak or western poison oak, is a woody vine or shrub widely distributed in western North America. It is common in various habitats, from riparian zones to dry chaparral. It thrives in shady and dappled light through full and direct sunlight conditions. It is one of the more common shrubs in California, growing throughout the coastal and coast mountain ranges, the Transverse mountain ranges, through the Sierra foothills, and in the Sacramento Valley. It is extremely variable in growth habit and leaf appearance, growing as a dense tall shrub in open sunlight, and a treelike vine or dense thickets in shaded areas. It reproduces by spreading rhizomes and by seeds. The plant is winter deciduous, so that after cold weather sets in, the stems are leafless and bear only the occasional cluster of berries.

Poison oak is known for causing itching and allergic rashes in many humans after contact by touch or smoke inhalation. Because of this, it is usually eradicated from gardens and public landscaped areas. However, it can be a carefully situated component in wildlife gardens, habitat gardens, and natural landscaping. The plant is used in habitat restoration projects. It can be early stage succession where woodlands have been burned or removed, serving as a nurse plant for other species.

Botanist John Howell observed the toxicity of Poison Oak obscures its merits: "In spring, the ivory flowers bloom on the sunny hill or in sheltered glade, in summer its fine green leaves contrast refreshingly with dried and tawny grassland, in autumn its colors flame more brilliantly than in any other native, but one great fault, its poisonous juice, nullifies its every other virtue and renders this beautiful shrub the most disparaged of all within our region."

Black-tailed deer, mule deer, California ground squirrels, western gray squirrels, and other indigenous fauna feed on the leaves of the plant. It is rich in phosphorus, calcium, and sulfur. Bird species use the berries for food, and utilize the plant structure for shelter. Neither native animals, nor horses, livestock, or canine pets demonstrate reactions.

Trianthema portulacastrum is a species of flowering plant in the ice plant family known by the common names desert horsepurslane, black pigweed, and giant pigweed. It is native to areas of several continents, including Africa and North and South America, and present as an introduced species in many other areas. It grows in a wide variety of habitat types and it can easily take hold in disturbed areas and cultivated land as a weed. It is an annual herb forming a prostrate mat or clump with stems up to a meter long. It is green to red in color, hairless except for small lines of hairs near the leaves, and fleshy. The leaves have small round or oval blades up to 4 centimeters long borne on short petioles. Solitary flowers occur in leaf axils. The flower lacks petals but has purple, petallike sepals. The fruit is a curved, cylindrical capsule emerging from the stem. It is up to half a centimeter long and has two erect, pointed wings on top, where the capsule opens. Seed dispersal occurs in a number of ways. One seed may be carried on the detached cap of the fruit, which floats on water. Other seeds may fall out of the remaining part of the fruit or remain on the plant after it dies and withers, resprouting the following season.

Trichostema austromontanum is a species of flowering plant in the mint family known by the common name San Jacinto bluecurls. It is native to California from the mountains east of the Sierra Nevada to the Transverse Ranges and Peninsular Ranges, its distribution extending south into Baja California. It occurs in wet mountain meadows and on the shores of lakes. It is an annual herb approaching half a meter in maximum height, its aromatic herbage coated in glandular and nonglandular hairs. The elongated or lance-shaped leaves are 2 to 5 centimeters long. The inflorescence is a series of clusters of flowers located at each leaf pair. Each flower has a hairy calyx of pointed sepals and a tubular, lipped purple corolla. The four stamens are long and curved. There are two subspecies. The rarer, ssp. compactum, the Hidden Lake bluecurls, is known only from one location at Hidden Lake, a small seasonal alpine lake in the San Jacinto Mountains of Riverside County, California. The main threat to its existence is trampling by hikers and sightseers.

Woolly Bluecurls (Trichostema lanatum) is named for its curled, fuzzy flowers that bloom in brilliant shades of blue and lavender. These striking flowers bloom in dense clusters on branching stems from fall to spring. A favorite of hummingbirds, the flowers also attract bees, butterflies, and other insects.

This shrub is a member of the Mint family. Its narrow, bright green leaves have a pleasant, minty fragrance. It can quickly grow to an impressive size in the first year, although as a fire-following plant, it does have a short lifespan (around 4 to 5 years).

In the garden, this plant requires specific growing conditions to do well. A young Woolly Bluecurls plant needs regular watering after planting. Once it's established, however, overwatering - even occasional summer water - can damage or kill them. Plant in full or part sun in light, well-draining soil. It does well in rocky areas and does not like mulch. Although short-lived, the showy blooms make this plant a stunning addition to a low-water pollinator garden.

The annual herb of the mint family Trichostema lanceolatum is commonly known as vinegar weed because its foliage contains volatile oils that have a strong vinegar odor. Other common names for the plant include terpentine weed and camphor weed. The oils also have phytotoxic properties, which help vinegar weed compete by killing or injuring other plant species. Indians of northern California used the plant as a cold and fever remedy, a pain reliever, and a flea repellent. Vinegar weed is a wildflower bearing striking purple-blue flowers on short green stems. The numerous leaves are juicy and green and are covered in fluffy hairs. The plant is well adapted to its native range in California, where it thrives in dry, nutrient-poor, sun-baked clay soil. In hot weather the vinegar smell of the plant becomes intense as the oils in the tissues permeate the air. The plants of this genus are sometimes called blue curls, but this name may be more associated with the similar, but sweeter smelling, species Trichostema lanatum. Vinegar weed is found on the west coast of North America from northern Mexico to southern Canada.

Trichostema laxum is a species of flowering plant in the mint family, known by the common name turpentine weed from the foliage's scent. The annual plant is native to northern California and Oregon, at elevations below 1,700 metres (5,600 ft). It is found primarily in the Inner Northern California Coast Ranges, including the subranges of the Klamath Mountains and the Mayacamas Mountains. It grows in gravelly streambanks or sandy soil, of the mountains and foothills in chaparral, Foothill oak woodland, and Yellow pine forest habitats. The species has an affinity for serpentine soils. Trichostema laxum is an annual herb approaching 5 decimetres (1. 6 ft) in maximum height. Its aromatic foliage, with a strong turpentine odor, is coated in glandular and nonglandular hairs. The lanceolate to narrowly ovate leaves are up to 7 centimeters long. The inflorescence is a series of clusters of flowers located at each leaf pair. Each flower has a hairy calyx of green or reddish sepals and a tubular, lipped purple corolla. The four stamens are long and curved, measuring up to 1. 6 centimeters in length. Its bloom period is from June to October.

Trichostema micranthum is a species of flowering plant in the mint family, known by the common name smallflower bluecurls. The plant is native to Southern California, northwestern Arizona, and northern Baja California state. In California populations are found in the San Bernardino Mountains and San Emigdio Mountains of the Transverse Ranges. Its habitat includes meadow wetlands and riparian riverbanks, often in white fir (Abies concolor) and Yellow pine forest habitats. It grows at 1,500-2,500 metres (4,900-8,200 ft) in elevation. Trichostema micranthum is an annual herb growing to under 3 decimetres (12 in) in maximum height. Its aromatic foliage is coated in short, glandular and nonglandular hairs. The pointed oval or lance-shaped leaves are up to 4. 5 centimeters long. The inflorescence is a series of clusters of flowers located at each leaf pair. Each flower has a hairy calyx of pointed sepals and a tubular, lipped purple corolla a few millimeters in length. The four stamens are sometimes protrude from the lips of the corolla.

Trichostema oblongum, known by the common names oblong bluecurls and mountain bluecurls, is a species of flowering plant in the mint family . It is native to California and the Northwestern United States in Oregon, Idaho, and Washington, and north into British Columbia, Canada. Trichostema oblongum is an annual herb approaching five decimeters (20 in) in maximum height. Its aromatic foliage is coated in glandular and nonglandular hairs. The elongated or lance-shaped leaves are 2 to 4 centimeters (0. 79 to 1. 57 in). The inflorescence is a series of clusters of flowers located at each leaf pair. Each flower has a hairy calyx of pointed sepals and a tubular, lipped purple corolla. The four curved stamens protrude from the lips of the flower.

Trichostema ovatum is an uncommon species of flowering plant in the mint family known by the common name San Joaquin bluecurls. It is endemic to the San Joaquin Valley of California, where it occurs in grassland habitat, as well as disturbed and alkali soils, such as chenopod scrub. Trichostema ovatum is an annual herb approaching 80 centimeters in maximum height, its aromatic herbage coated in woolly glandular and nonglandular hairs. The pointed oval leaves are 1 or 2 centimeters long. The inflorescence is a series of clusters of flowers located at each leaf pair. Each flower has a hairy calyx of pointed sepals and a tubular, lipped purple corolla. The four stamens are long and curved, measuring up to 1. 6 centimeters long. The plant blooms in May through October, with peak flowering in the hot summer. Adequate rainfall is necessary for germination.

Trichostema parishii is a species of flowering plant in the mint family known by the common name Parish's bluecurls. It is native to the Transverse Ranges and Peninsular Ranges of southern California and south into Baja California. Its habitat includes chaparral and coastal sage scrub. It grows at 600-2,000 metres (2,000-6,600 ft) in elevation. Trichostema parishii is a shrub that grows to a maximum height around 12 decimetres (3. 9 ft). Its aromatic herbage coated in short glandular and nonglandular hairs. The linear leaves are up to 6 centimeters long. Their edges curl under, and they are hairy, especially on the undersides. A cluster of smaller leaves may occur in the axils of each main leaf. The inflorescence is a long cyme of flowers growing from the stem between each leaf pair. The inflorescence is coated in fluffy, woolly hairs in shades of blue, pink and purple. Each flower has a hairy calyx of pointed sepals and a tubular, lipped purple corolla, the main lower lip measuring up to a centimeter in length. The four stamens are long and curved, measuring up to 2. 5 centimeters long. Its bloom period is from March to May.

Trichostema rubisepalum is a species of flowering plant in the mint family known by the common name Hernandez's bluecurls. The plant is endemic to California. It has a disjunct distribution occurring in two main locations: the southern Diablo Range east of the Salinas Valley in San Benito County, and the western Sierra Nevada foothills, primarily within Mariposa County and Tuolumne County. Its habitats include chaparral, foothill oak woodland, mixed evergreen forest, intermittent streambeds, and seasonal pools. It has an affinity to serpentine soils. Trichostema rubisepalum is annual herb that grows to approximately 0. 5 metres (1. 6 ft) in maximum height. Its aromatic foliage is coated in long and short glandular and nonglandular hairs. The leaves are lance-shaped. The inflorescence is a long cyme of flowers growing from the stem between each leaf pair. Each flower has a hairy calyx of pointed sepals which often take on a dark red coloration. The flower has a tubular throat and a lipped, purple corolla. The four protruding, curved stamens are about half a centimeter long. Its bloom period is from June to July.

Trichostema ruygtii, with the common name Napa bluecurls, is a species of flowering plant in the mint family. It was first described to science in 2006. The plant is endemic to California in the northern San Francisco Bay Area, where it is known from the southern Mayacamas Mountains, in Napa County and into western Solano County. Its habitats include chaparral, oak woodland, mixed evergreen forest, and vernal pools in grasslands. Trichostema ruygtii is an annual herb that grows under 5 decimetres (1. 6 ft) in height. The stems and lanceolate leaves have short hairs. The flowers are a pale lavender in color. Its bloom period is June to October. The species is threatened by agriculture and development. Trichostema ruygtii is listed as a Critically endangered species on the California Native Plant Society Inventory of Rare and Endangered Plants.

Trichostema simulatum is a species of flowering plant in the mint family known by the common name Siskiyou bluecurls. It is native to the southern Cascade Range in northern California and southern Oregon, and in the northern Sierra Nevada in California. Trichostema simulatum is an annual herb grows up to about 40 centimetres (16 in) tall. Its aromatic foliage is coated in long and short glandular and nonglandular hairs. The lance-shaped leaves are 2 to 5 centimeters long. The inflorescence is a long cyme of flowers growing from the stem between each leaf pair. Each flower has a hairy calyx of sepals with triangular points and a tubular, lipped purple corolla. The four protruding stamens are curved.

Tridens muticus is a species of grass known by the common name slim tridens. It is native to Mexico and the southwestern quadrant of the United States, where it grows several types of habitat, including plateau and desert, woodlands, sagebrush, plains, and other areas with dry sandy and clay soils. It is a perennial grass forming a thick tuft with a knotted base and rhizome. It reaches a maximum height of 50 to 80 centimeters. The panicle has short branches appressed to the others, making the inflorescence narrow. The florets are generally purple in color.

Trifolium albopurpureum is a species of clover known by the common name rancheria clover. It is native to the west coast and of North America from British Columbia, California and the Sierra Nevada, to Baja California. It can be found in a wide variety of habitats, including chaparral and woodlands, grasslands, forests, and montane locales. Trifolium albopurpureum is an annual herb growing decumbent or erect in form. The leaflets are 1 to 3 centimeters long, and the herbage is hairy. The inflorescence is a spike of flowers measuring 0. 5 to 2 centimeters wide. Each flower has a calyx of sepals with narrow lobes that taper into a bristle-shaped point and are coated in long hairs. Within the calyx is the flower corolla, which is purple and white in color. Subspecies. Trifolium albopurpureum is often discussed as comprising three Varieties: These are:Trifolium albopurpureum var. albopurpureumTrifolium albopurpureum var. dichotomumTrifolium albopurpureum var. olivaceum

Trifolium amoenum, known by the common names showy Indian clover and two-fork clover, is endemic to California, and is an endangered annual herb that subsists in grassland areas of the San Francisco Bay Area and the northern California Coast Ranges. This wildflower has an erect growth habit and is typically found on heavy soils at elevations less than 100 meters. The flower head is somewhat spherical with a diameter of about 2. 5 centimeters. The petals are purple gradating to white tips. History and Edward Lee Greene collected the first recorded specimen of this plant in 1890 in Vacaville, California Solano County. The historical range of Trifolium amoenum was from the western extreme of the Sacramento Valley in Solano County west and north to Marin and Sonoma Counties, where many sites were presumed extirpated by urban and agricultural development. Due to the further expansion of the human population, Trifolium amoenum became a rare species by the mid-1900s. Through the latter 1900s, the number of distinct populations dwindled to about 20 in number, from pressure of an expanding human population and urban development. Rediscovery. By 1993 Trifolium amoenum was thought to be extinct, after the population in Vacaville, California depleted, but was rediscovered by Peter Connors in the form of a single plant on a site in western Sonoma County. The seeds from this single plant organism were used to grow more specimens. The Sonoma County location has been developed and any plants remaining there have been extirpated. Presently there is only a single extant population, subsequently discovered in 1996 in northern Marin County, which numbers approximately 200 plants. Trifolium amoenum became a federally listed endangered species in 1997. Recent conservation research on Trifolium amoenum has been conducted by the Bodega Marine Laboratory.

Trifolium andersonii is a species of clover known by the common names fiveleaf clover and Anderson's clover. It is native to the western United States, particularly the Great Basin and adjacent high mountain ranges, including the Sierra Nevada. It grows in forests, mountain meadows, and talus. It has been noted to be the dominant species in dry areas on the alpine grassland steppe in the White Mountains of California. Trifolium andersonii is a perennial herb growing in a tuft or low cushion, and lacking a stem. The long-haired or woolly, silvery-gray leaves have 3 to 7 leaflets each up to 2 centimeters long. The inflorescence is a head of flowers measuring 1. 5 to 2. 5 centimeters wide. Each flower has a calyx of sepals with narrow, densely hairy lobes. Within the calyx is the flower corolla, which is pinkish purple or bicolored. Various subtaxa are usually recognized by authors as varieties or subspecies.

Trifolium barbigerum is a species of clover known by the common name bearded clover. The plant is native to central coastal and Northern California and Oregon, below 700 metres (2,300 ft) in elevation. Areas it is found include on the northern Channel Islands of California, the California Coast Ranges, and around the San Francisco Bay Area. It grows in many types of habitat, including coastal prairie, mixed evergreen forest, closed-cone pine forest, and wetland-riparian areas. It is also found in disturbed and cultivated areas. Trifolium barbigerum is an annual herb growing decumbent to erect in form and hairy to hairless in texture. The leaves are divided into oval leaflets up to 2. 5 centimeters long, sometimes having notches at the tips. The stipules on the leaves are large and variable in shape. The inflorescence is a head of flowers up to 2. 5 centimeters wide. The flowers are held in a bowl-shaped involucre of bracts with toothed edges. Each flower has a calyx of sepals narrowing into one or more bristles which are coated with long hairs. Within each calyx is the flower corolla which may be pinkish purple, white, or bicolored purple and white. The bloom period is April to July. Varieties: Trifolium barbigerum was formerly discussed classified with two varieties, that are not in current use:Trifolium barbigerum var. andrewsii - reclassified as Trifolium grayi. Trifolium. barbigerum var. barbigerum - reclassified as and synonym of Trifolium barbigerum.

Trifolium beckwithii is a species of clover known by the common name Beckwith's clover. It is native to the western United States, from northeastern California, Oregon, Nevada and Utah in the Great Basin region, to Montana and into South Dakota. Habitats include yellow pine forest, red fir forest, mountain meadows, and wetland-riparian areas. Trifolium beckwithii is a perennial herb growing upright in form. Most of the leaves are basal, except for one pair growing higher on the stem. The leaf is made up of oval leaflets up to 4 centimeters long and the stipules are large. The inflorescence is a head of flowers 2 to 3 centimeters wide. The flower corolla is pink, purplish, or bicolored. The flowers droop on the head as they age.

Trifolium bifidum is a species of clover known by the common names notchleaf clover and pinole clover. It is native to the western United States from Washington to California, where it grows in many types of habitat. It is an annual herb spreading or growing erect in form. It is lightly hairy to hairless in texture. The leaves are made up of oval leaflets 1 to 2 centimeters long, usually with notches in the tips. The inflorescence is a head of flowers up to 1. 5 centimeters wide. Each flower has a calyx of sepals that narrow to bristles covered in long hairs. The flower corolla is yellowish, pinkish, or purple and under a centimeter long. The flowers droop on the head as they age. Trifolium depauperatum is often discussed as comprising two Varieties: These are:

Pinole Clover (Trifolium bifidum var. bifidum) is a native annual herb that grows in central and northern California. It tends to grow in open, grassy places, at elevations from 0-2000 feet.

Notch Leaf Clover (Trifolium bifidum var. decipiens) is a native annual herb that grows in northern, southern and central California. It tends to grow in open, grassy places, at elevations from 0-3300 feet.

Trifolium bolanderi is a species of clover known by the common names Bolander's clover and parasol clover. The perennial herb is endemic to California. It is known only from the meadows of the central Sierra Nevada in Lower and Upper montane coniferous forest habitats, with small populations in Fresno County, Madera County, and Mariposa County. It is listed as a Vulnerable species by the California Department of Fish and Wildlife and IUCN, and is on the California Native Plant Society Inventory of Rare and Endangered Plants as a Fairly endangered species. Trifolium bolanderi is a perennial herb growing in clumps with upright stems and mostly hairless herbage. The leaves are arranged around the base of the stem. Each is made up of oval leaflets with toothed edges. The inflorescence is a head of flowers 1 or 2 centimeters wide, the flowers soon drooping to hang from the head in a parasol-shaped arrangement. Each flower has a calyx of dark purple or black sepals that contrasts with the pale pinkish corolla. The tubular corolla measures just over a centimeter long.

Trifolium breweri, which has the common names forest clover and Brewer's clover, is a perennial clover that is native to mixed evergreen forests and coastal coniferous forests in southern Oregon and California. It belongs to the family Fabaceae, known for containing peas and other legumes. Its genus, Trifolium, has a cosmopolitan distribution; the densest of which is found in the Northern Hemisphere. Trifolium breweri is found in southern Oregon and California. It grows in the Klamath Range, Cascades Range, and Sierra Nevada. This plant is considered to be secure within its range. Recent Research. There was a study done about New World clovers found in mountainous regions done in 2013. Trifolium breweri is mentioned briefly as being basal within the Involucrarium clade with some of the South American species that were studied. Another study done on the molecular phylogenetics of the clover genus mentions Trifolium breweri. 218 species of Trifolium were collected and sequenced in California. The results of the study were consistent with a Mediterranean origin of the genus, probably in the Early Miocene. They believe that all of the New World species had a single origin, while the species of sub-Saharan Africa originated from three separate dispersal events.

Trifolium buckwestiorum is a rare species of clover known by the common name Santa Cruz clover. It is endemic to California, where it is known from nine or ten small occurrences in Monterey, Santa Cruz, and Sonoma Counties. It may also occur in San Mateo, Santa Clara, and Mendocino Counties, but its populations are very small and easily disturbed by threats such as vehicles, development, and feral pig activity. It grows in forest, woodland, and coastal prairie habitat. It is an annual herb growing upright or decumbent in form, with hairless green or reddish herbage. The leaves are made up of finely toothed, oval shaped leaflets up to 1. 5 centimeters long and bristle-tipped stipules. The inflorescence is a head of flowers roughly a centimeter wide, the flowers held in a bowl-like involucre of wide, jagged-toothed bracts. Each flower has a calyx of sepals that narrow into fine bristles and a pink corolla under one centimeter long.

Foothill Clover (Trifolium ciliolatum) is a common native annual herb that grows in northern, southern and central California. It tends to grow in open, grassy places, at elevations from 0-5000 feet.

Trifolium cyathiferum is a species of clover known by the common names cup clover and bowl clover. This species occurs in western North America, its distribution extending from Alaska and the Yukon, through the Pacific Northwest to California, Utah, and Montana. As an example occurrence, it is found in the California Coast Ranges in such places as Ring Mountain, California, where it is found in association with tomcat clover. It usually occurs in spring-moist valleys, chaparral, and forest habitats, below 2,500 metres (8,200 ft) in elevation. Trifolium cyathiferum is a low growing annual plant. The inflorescence is many flowered and bowl shaped. Flowers are white to yellow with pink tips. The bloom period is May to August.

Trifolium depauperatum is a species of clover known by the common names cowbag clover, poverty clover, and balloon sack clover. The plant is native to western North America from British Columbia to California, as well as towestern South America in Peru and Chile. It is a common plant of many types of habitat, including coastal prairie and mixed evergreen forest,. Trifolium depauperatum is a small annual herb growing upright or decumbent in form. The leaves are made up of oval leaflets up to 2 centimeters long which are smooth, toothed, lobed, or blunt-tipped. The inflorescence is a head of flowers up to 1. 5 centimeters long. The flower has a pinkish purple white-tipped corolla up to a centimeter long. It becomes inflated as the fruit developed. Subspecies. Trifolium depauperatum has several varieties, which can include:Trifolium depauperatum var. amplectens - Balloon sack clover, Pale bladder clover. Trifolium depauperatum var. depauperatum - Cowbag clover. Trifolium depauperatum var. hydrophilumTrifolium depauperatum var. truncatum - Dwarf sack clover.

Trifolium eriocephalum is a species of clover known by the common name woollyhead clover or hairy head clover. The plant is native to the Northwestern United States, and to California, Nevada, and Utah. It is a common plant of several types of habitat, including Coast redwood forest, coastal prairie, mixed evergreen forest, and yellow pine forest. Trifolium eriocephalum is a hairy perennial herb producing an upright, unbranched stem. The leaves are made up of oval leaflets up to 4 centimeters long. The inflorescence is a head of flowers up to 3 centimeters long with flowers spreading and soon drooping. The flower has a densely hairy, tubular calyx of sepals with long, narrow linear lobes that may bend outward. The white or yellowish corolla may be up to 1. 4 centimeters long. Subspecies are: Trifolium eriocephalum ssp. cusickii - Cusick's clover, Great Basin region. Trifolium eriocephalum ssp. eriocephalum

Trifolium fucatum is a species of clover known by the common names bull clover and sour clover. It is native to California and Oregon, where it grows in many types of habitat, becoming common to abundant in some areas. Trifolium fucatum is an annual herb growing decumbent to erect in form, the stem often thick-walled and hollow. The leaf blades are made up of oval or rounded leaflets with smooth or toothed edges, and the leaves have large stipules. The inflorescence is a head of flowers with a base of wide bracts. Each flower corolla is 1 to 2 centimeters long and white or yellowish with purple tips. The flower becomes inflated as the fruit develops.

Trifolium gracilentum is a species of clover known by the common names pinpoint clover and slender clover. It is native to western North America including the west coast of the United States and northwestern Mexico, where it grows in many types of habitat, including disturbed areas. It is an annual herb growing prostrate to erect in form with mostly hairless or slightly hairy herbage. The leaves are made up of lance-shaped to oval leaflets. The inflorescence is an umbel of flowers that spread out or flex downward. The flowers have pink or purple corollas less than a centimeter long. One variety of this species, var. palmeri, is a rare plant limited to the Channel Islands of California; it is sometimes treated as a species in its own right, Trifolium palmeri.

Trifolium gymnocarpon is a species of clover known by the common name hollyleaf clover. It is native to the western United States, from California to New Mexico, and Oregon to Montana. It can be found in many types of habitat, including sagebrush scrub. Trifolium gymnocarpon is a small perennial herb with stems spreading along the ground to form a flat mat or clump. The leaves are each made up of 3 to 5 thick, hairy leaflets with serrated edges. The inflorescence is an umbel of flowers spreading out or flexing downward. The flower is roughly a half inch long and dull pink or brownish in color.

Trifolium howellii is a species of clover known by the common names canyon clover and Howell's clover. It is native to Oregon and California, where it grows in moist and shady habitat types, such as swamps and forest streambanks. It is a perennial herb growing erect with hairless herbage. The leaf blades are made up of large oval leaflets each measuring up to 10 centimeters long, and large stipules which may be over 2 centimeters long. It is a perennial herb growing erect with hairless herbage. The leaf blades are made up of large oval leaflets each measuring up to 10 centimeters long, and large stipules which may be over 2 centimeters long. The inflorescence is a round or elongated head of flowers up to 3 centimeters long, the flowers spreading out and drooping with age. Each flower has a greenish or pinkish corolla measuring one centimeter long or more.