Kellogg's Horkelia (Horkelia cuneata ssp. sericea) is a rare native perennial herb that grows in Southern and Central California, primarily in the Central Coast region. It tends to grow in dunes, at elevations from 0-2300 feet.

Horkelia daucifolia is a species of flowering plant in the rose family known by the common name carrotleaf horkelia. It is native to the Klamath Mountains and surrounding ranges in northern California and southern Oregon, where it grows in mountain slopes and fields, often on serpentine soils. This is a perennial herb producing a rosette of leaves each five to 15 centimeters long. Each leaf is made up of lobed, hairy leaflets each one or two centimeters long. The plant produces erect stems up to 30 centimeters tall and bright red or greenish in color. The inflorescence holds several flowers, each with narrow, pointed bractlets and wider, reflexed green or pinkish sepals. The five narrow petals are white, yellow, or pink.

Horkelia fusca is a species of flowering plant in the rose family known by several common names, including pinewoods horkelia and dusky horkelia. It is native to the western United States from California to Wyoming, where it is generally found in mountain forests and meadows. This perennial herb forms a thick tuft of leaves, each growing erect up to 15 centimeters tall. Each leaf is made up of wedge-shaped or rounded leaflets with toothed or lobed edges. These are often gray-green and somewhat hairy. The brown or reddish hairy stem reaches a maximum height near 60 centimeters and holds an inflorescence of several clusters of flowers. Each flower has small, pointed bractlets beneath larger green, red, or magenta sepals and five white to pinkish petals. The center of the flower has a ring of ten stamens around a bunch of 10 to 20 small pistils. There are several subspecies, including:

Horkelia hendersonii is a rare species of flowering plant in the rose family known by the common name Henderson's horkelia. It is known from four populations in southern Oregon, including Mount Ashland, and one population south of the border in Siskiyou County, California. It is a resident of dry forest habitat in the granite soils of the Klamath Mountains. This is a perennial herb producing a low mat of hairy, hairy gray-green foliage about a woody base. The leaves are cylindrical and sometimes tapering to a point, growing erect in a patch around the caudex. Each leaf is 3 to 8 centimeters long and is made up of densely spaced pairs of minutely toothed leaflets. The leaflets are coated in silky hairs. The flower cluster is a dense array flowers atop an erect stalk, each flower made up of five hairy, pointed sepals and five smaller, more delicate white petals. Although few populations of the plant are known to exist, they are not in imminent danger of destruction and a federal listing as an endangered or threatened species was declined in 2003. The Mount Ashland populations of this plant are sometimes threatened by recreational activities at that site, including skiing and maintenance of ski facilities, and off-road vehicle use.

Horkelia hispidula is a species of flowering plant in the rose family known by the common name White Mountains horkelia. It is endemic to the White Mountains, a small mountain range that straddles the border between California and Nevada east of the Sierra Nevada. It is a resident of dry scrub and alpine and subalpine forest habitat. This is a perennial herb producing a low mat of hairy, glandular greenish gray foliage about a woody base. The leaves are cylindrical and sometimes taper to a point, growing erect in a patch around the caudex. Each leaf is up to 10 centimeters long and is made up of crowded pairs of hairy leaflets. The inflorescence is an array of up to 15 flowers atop an erect stalk, each flower made up of five hairy, pointed, reflexed sepals and five white petals.

Horkelia marinensis is a rare species of flowering plant in the rose family known by the common name Point Reyes horkelia. It is endemic to the California coastline, where it is known from about Fort Bragg to near Santa Cruz. It grows on beaches and in other sandy coastal areas. This is a perennial herb growing in low, dense patches. The leaves are up to 10 centimeters long and are made up of toothed, hairy, gray-green leaflets each around a centimeter long. The foliage is glandular and strongly scented. The plant produces green to reddish-green stems up to 30 centimeters long which bear inflorescences of dense clustered flowers. Each flower has minute bractlets under reddish-green, fuzzy sepals. The petals are generally white and narrow with rounded ends. The center of the flower contains a ring of stamens around a patch of 20 to 30 pistils.

Horkelia parryi is a species of flowering plant in the rose family known by the common name Parry's horkelia. It is endemic to California, where it grows in the chaparral of the Sierra Nevada foothills. This is a low, mat-forming perennial herb growing in unobtrusive green patches on the ground. The leaves are 5 to 10 centimeters long and are each made up of small, toothed, oval-shaped leaflets. The somewhat hairy green to reddish-green stems are 10 to 30 centimeters long and bear inflorescences of a few flowers each. The flower has minute bractlets under larger, pointed sepals and five white petals. The center of the flower contains a ring of stamens around a patch of up to 50 thready pistils.

Horkelia rydbergii is a species of flowering plant in the rose family known by the common name Rydberg's horkelia. It is endemic to the Transverse Ranges of southern California, where it grows in several types of habitat, including pine forest. This is a perennial herb producing a low mat of hairy, hairy gray-green foliage around a woody base. The leaves are mostly flat and made up of pairs of hairy, wedge-shaped leaflets with toothed tips. The flower cluster is an open array of up to 40 flowers atop an erect stalk, each flower made up of five pointed green sepals and five white petals. At the center of the flower is a cone of 10 stamens around a bunch of up to 50 pistils.

Horkelia sericata is a species of flowering plant in the rose family known by the common names silky horkelia and Howell's horkelia. It is native to the Klamath Mountains of northern California and southern Oregon, where it grows in the chaparral and forest, often on serpentine soils. This is a perennial herb growing in small tufts of erect leaves and stems. The leaves are 3 to 15 centimeters long and are each made up of herringbonelike rows of small, tightly packed leaflets. The green leaflets bear long, silky white hairs, giving the plant a silvery green look. The green, brown, or reddish stems reach up to 50 centimeters long and bear loose inflorescences of many flowers. The flower has small green sepals covered in luxuriant white hairs, and white or pink-tinted petals with two-lobed tips.

Horkelia tenuiloba is a species of flowering plant in the rose family known by the common names Santa Rosa horkelia and thin-lobed horkelia. It is endemic to California, where it is known only from the coastal hills and mountains north of the San Francisco Bay Area. It is a plant of chaparral habitat. This is a perennial herb producing a low mat of hairy, glandular green foliage around a woody base. The leaves are cylindrical or somewhat flat, often tapering to a point, and each is made up of several densely packed pairs of hairy leaflets. The inflorescence is an array of flowers atop an erect stalk, each flower made up of five pointed green sepals and five white petals. At the center of the flower is a cone of stamens tipped with reddish anthers around many pistils.

Horkelia tridentata is a species of flowering plant in the rose family known by the common name threetooth horkelia. It is native to all of the mountain ranges of northern California and southern Oregon, where it grows in coniferous forest. This is a perennial herb forming tufts of erect leaves and stems. The leaves are 3 to 12 centimeters long, each made up of hairy gray-green leaflets which are tipped with usually three teeth. Unlike many other horkelias, this species is generally not strongly scented. The green or reddish stems reach a maximum length of about 40 centimeters and hold clusters of flowers. Each flower has minute bractlets beneath small, hairy, pointed sepals and narrow white petals.

Horkelia truncata is a species of flowering plant in the rose family known by the common name Ramona horkelia. It is native to the Peninsular Ranges of southern California and northern Baja California, where it grows in the chaparral. This is a clumpy perennial herb forming tufts of erect leaves and stems. The leaves are up to 13 centimeters long and are made up of large oval-shaped leaflets with toothed edges and squared-off, toothed tips. The terminal leaflet of the leaf is sometimes untoothed. The thin stem is 20 to 60 centimeters tall and holds an flower cluster of several flowers. Each flower has short sepals beneath five round white petals. The center of the flower contains a ring of stamens around a patch of up to 80 thready pistils.

Horkelia tularensis is a species of flowering plant in the rose family known by the common name Kern Plateau horkelia. It is endemic to Tulare County, California, where it is known from about ten occurrences in the High Sierra Nevada. It grows in rocky, exposed areas. This is a mat-forming perennial herb producing clumps of short, erect leaves and stems. The leaves are up to about 10 centimeters long and are made up of small closely packed leaflets. The foliage is covered in hairs that give the plant a light gray-green color. Stems grow to about 20 centimeters in maximum height and hold inflorescences of several flowers each. The flower has pointed green sepals up to half a centimeter long and shorter, narrow white petals.

Horkelia wilderae is a rare species of flowering plant in the rose family known by the common name Barton Flats horkelia. It is endemic to San Bernardino County, California, where it is known from only about ten occurrences in the vicinity of Barton Flats. It grows in the montane chaparral and woodlands habitat where chaparral meets pine forest, and it is threatened by logging. Horkelia wilderae is a perennial herb producing an inconspicuous rosette of prostrate leaves around a small caudex. Each leaf is up to 10 centimeters long and is made up of several pairs of wedge-shaped leaflets divided at the tips into several lobes. The inflorescence is an open array of up to 15 flowers atop an erect stalk, each flower made up of five pointed, green, often recurved sepals and five wedge-shaped to oblong white petals. Horkelia wilderae is a perennial herb producing an inconspicuous rosette of prostrate leaves around a small caudex. Each leaf is up to 10 centimeters long and is made up of several pairs of wedge-shaped leaflets divided at the tips into several lobes. The inflorescence is an open array of up to 15 flowers atop an erect stalk, each flower made up of five pointed, green, often recurved sepals and five wedge-shaped to oblong white petals.

Horsfordia alata (pink velvetmallow) is a shrubby plant in the mallow family (Malvaceae) native to the Sonoran Desert. :103

Lotus crassifolius is a species of trefoil, a legume, known by the common names big deervetch and broad-leafed lotus. It is a long-lived, somewhat bushy plant which bears long straight stems with evenly spaced oval-shaped leaves. It produces thick bunches of yellow or pink-and-yellow pea flowers and brownish pea pods containing speckled red or brown peas. This legume is native to the western United States. One very rare variety of this plant is found only on Otay Mountain in southern San Diego County, California. Other varieties are much more common and can be found in chaparral ecosystems.

Big Deervetch (Lotus crassifolius var. crassifolius) is a native perennial herb that grows in northern, southern and central California. It tends to grow at elevations from 1000-6900 feet.

Otay Mtn. Lotus is a rare native perennial herb in the Fabaceae (Legume) family. It is one of two recognized varieties of Hosackia crassifolia found in California. It is found primarily in the Otay Mountain area of San Diego County and adjacent Baja, although there is also a disjunct population reported in San Luis Obispo County. The more common var. crassifolia also occurs in the same area of San Diego. Otay Mountain Lotus tends to grow in chaparral or disturbed areas at elevations from 1,000 to 4,000 feet. This plant is rarely used in gardens, a little information is available on its cultural tolerances and requirements.

Hosackia gracilis is a species in the Fabaceae (Legume) family known by the common name Seaside Bird's-foot Trefoil. It is a rare plant native to western North America from British Columbia to California, as far south as San Luis Obispo County, where it grows in moist spots in the coastal mountains and down to the oceanside bluffs. Due to its limited distribution it is included on CNPS list 4.2. It is a perennial herb growing upright or spreading to about half a meter in maximum length. It is lined with leaves each made up of a few oppositely arranged oval leaflets up to 2 centimeters long. The flower cluster is made up of several pea-like flowers each 1 to 2 centimeters long. The flower has a bright yellow banner, or upper petal, and bright pink or white lower petals. The fruit is a legume pod 2 or 3 centimeters long.

Lotus oblongifolius is a species of legume known by the common name streambank bird's-foot trefoil. It is native to western North America from Oregon to northern Mexico, where it grows in moist to wet areas in several types of habitat. It is a spreading or upright perennial herb lined with leaves each made up of elongated oval leaflets each up to 2.5 centimeters long. The flower cluster bears several yellow and white flowers between 1 and 2 centimeters long. The fruit is very elongated, reaching up to 5 centimeters in length but just a few millimeters in width. One variety of this species, var. cupreus, the copper-flowered bird's-foot trefoil, is endemic to the Sierra Nevada slopes of Tulare County, California.

Yolla Bolly Mtns. Bird's Foot Trefoil (Lotus yollabolliensis) is a rare native perennial herb that grows in Northern California, primarily in the North Coast and North Coast Range regions. It tends to grow in open and dry slopes, at elevations from 5600-6900 feet.

Howellanthus is a monotypic genus of flowering plants in the borage family containing the single species Howellanthus dalesianus, commonly known as Scott Mountain phacelia or Howell's phacelia. Until 2010 the plant was known as Phacelia dalesiana. It is endemic to the southern Klamath Mountains of northern California, including the Scott Mountains for which it is named. It grows in mountain forests and meadows. Phacelia dalesiana is a perennial herb producing a few decumbent stems up to about 15 centimeters long, forming a patch on the ground. It is glandular and hairy in texture. The leaves are located in a rosette, with a few smaller ones along the stems. They are oval and smooth-edged. The inflorescence is a small curving cluster of flowers each just under a centimeter wide. The flower is white with small purple streaks at the throat. There are five protruding stamens tipped with large purple anthers. It blooms between May and August, the timing dependent on snowmelt. Ecology. The plant is a paleoendemic, its morphology unique among the phacelias, and probably a relict persisting in areas of ultramafic rock substrate in a small section of the Siskiyou-Trinity Mountains. Taxonomy. The new name honors botanist John Thomas Howell and his friend, plant collector Ella Dales Miles Cantelow. The type location is the summit of Scott Mountain in Trinity County, California, near California State Route 3 and the Pacific Crest Trail, the type locality for many species of rare endemic plants.

Howellia aquatilis (water howellia) is a small plant in the family Campanulaceae and is considered to a threatened species since 1994. It is the only species in the monotypic genus Howellia. Thomas Jefferson Howell and Joseph Howell discovered the species in 1878. The water howellia is found in large area of the Pacific Northwest region of the United States. It can be found in California, Idaho, Montana, and Washington, and it is known historically from Oregon. The plant grows in wetland habitat surrounded by forests, which provide organic material. Associated tree species include Populus trichocarpa (California poplar), P. tremuloides (quaking aspen), and Fraxinus latifolia (Oregon ash). The water bodies are located in glacial potholes, river oxbows, ephemeral ponds, flood plains and other areas that fill with water periodically as snow melts and spring rain falls. Biology. The plant produces two types of flowers. Submerged cleistogamous flowers remain closed and self-pollinate, and flowers that bloom above the surface of the water open into white blossoms and may cross with other individuals. Because it often pollinates itself, the species has a low genetic diversity. Seeds are produced in the water but they require open air for germination, so they sprout when the wetland has dried in the fall. Threats to this species include loss of habitat to logging and draining and conversion to urban use, alteration of the local hydrology by placement of dams and dikes, deposition of silt, livestock activity, introduced species of plants, low genetic diversity, and climate change.

Hulsea algida is a species of flowering plant in the daisy family, known by the common name Pacific hulsea or alpine gold. Hulsea algida is native to California, Oregon, Nevada, Idaho, Montana, and Wyoming. Within California, it grows in the Sierra Nevada and in the White Mountains. It grows between 9,500 and 14,000 feet (2,900 and 4,300 m) in elevation, in alpine and subalpine talus habitats.

Hulsea brevifolia is a species of flowering plant in the daisy family known by the common name shortleaf alpinegold, or shortleaf hulsea. It is endemic to California, where it is an uncommon resident of the High Sierra. It is found between 6,000-8,000 feet (1,800-2,400 m) in elevation. Hulsea brevifolia is a perennial herb producing loose tufts of erect stems 30 to 60 centimeters (1-2 feet) tall. The green stems and foliage are covered in glandular hairs. The faintly toothed leaves occur basally and also along the stems. They are 5 to 6 millimeters (0. 20-0. 24 inches) long and have petioles with stiff hairs along the edges. The daisylike flower heads are up to 2 centimeters (0. 8 inches) wide and have long, hairy, lance-shaped green phyllaries. The center of the head is filled thickly with long yellow disc florets and the circumference is lined with 10-23 yellow ray florets. The fruit is an achene 6 to 8 centimeters (2. 4-3. 2 inches) long bearing a pappus which may be red-tinged.

Hulsea californica is a rare species of flowering plant in the daisy family known by the common names San Diego alpinegold and San Diego sunflower. It is endemic to southern California, where it grows only in the Peninsular Ranges. The plant grows in open areas such as forest clearings and occurs in the chaparral, especially after wildfire. Most of its known populations are in San Diego County. The main threat to this species are invasive plant species. Hulsea californica is a clumpy biennial herb producing greenish-gray to reddish erect stems of 40 centimeters (16 inches) to over a meter (40 inches) in height. The stems and foliage are hairy to densely woolly with thick coats of cobwebby fibers. Plants with thicker fibers are gray in color to nearly white. The abundant leaves are lance-shaped to scoop-shaped and up to 10 centimeters (4 inches) long, mostly without teeth along the edges but sometimes wavy or coarsely lobed. The flower head is large with woolly lance-shaped phyllaries each over a centimeter (0. 4 inches) long. The center of the head is packed with a large number of tiny deep yellow disc florets. This is surrounded by 22-40 yellow ray florets, each ray up to two centimeters (0. 8 inches) long.

Hulsea heterochroma is a species of flowering plant in the daisy family known by the common name redray alpinegold. It is native to the southwestern United States where it grows in open habitats. This is an annual or perennial herb growing thick, leafy green stems to maximum heights over one meter. The toothed leaves are 10 to 20 centimeters long. Leaves and stem are covered in hairy hairs. The leafy flower cluster produces many flower heads also completely covered in small hairy hairs. The green, lance-shaped phyllaries are over a centimeter long. The center of the flower head is filled with large yellow disc florets and the edge is fringed with narrow, thready red-orange to reddish pink ray florets each up to a centimeter long. The fruit is a hairy achene 6 to 8 millimeters long.

Hulsea mexicana, the Mexican alpinegold or Mexican hulsea is a rare North American species of flowering plant in the daisy familyIt has been found only in a small region straddling the border between Mexico and the United States. It grows in northern Baja California and in southern California (Imperial County and San Diego County). It grows in chaparral, yellow pine forests, and open habitats between 3,000-9,000 feet (910-2,740 m) in elevation. Indeed, the first botanical specimens collected were from the Mexican side of the border. Hulsea mexicana is an annuals or biennial herb sometimes reaching 100 cm (39 in) in height. Most of the leaves are on the stem rather than clustered around the base. One plant will generally produce 3-5 flower heads, each with 20-35 ray flowers surrounding a large number of tiny disc flowers.

Hulsea nana is a North American species of flowering plant in the daisy family known by the common name dwarf alpinegold. It is native to the western United States from Washington, Oregon, and far northern California. The plant grows in the talus of volcanic mountains and plateaus, in and near the Cascades. Hulsea nana is a diminutive perennial herb producing clumps of hairy foliage and stout stems rarely more than 20 centimeters (6 inches) tall. The leaves are 2 to 6 centimeters (0. 4-2. 4 inches) long and have lobed edges and many glandular hairs. The stem usually bears a single robust flower head with layers of hairy to woolly phyllaries. The center of the head is packed with golden disc florets surrounded by a circumference lined with golden ray florets each about a centimeter (0. 4 inches) long.

Hulsea vestita is a species of flowering plant in the daisy family known by the common name pumice alpinegold. It is native to eastern and southern California, where various subspecies grow in separate mountain ranges from the High Sierra to the Transverse Ranges and Peninsular Ranges, and Madrean Sky Islands in the Mojave Desert. One subspecies (Hulsea vestita ssp. inyoensis) also occurs in western Nevada. Hulsea vestita is a perennial herb growing a basal patch of thick leaves and stems up to a meter (40 inches) tall, but generally much shorter. The woolly, spoon-shaped leaves are gray-green and may have ruffled edges. The thick flower heads have glandular, hairy green phyllaries. The center of the daisylike head contains many long golden disc florets and a fringe of golden to reddish ray florets up to 2 centimeters (0. 8 inches) long. SubspeciesSubspecies of Hulsea vestita include:Hulsea vestita ssp. callicarpha (beautiful hulsea) - Southern California Hulsea vestita ssp. gabrielensis (San Gabriel Mtns. sunflower) - San Gabriel Mountains, other Transverse Ranges. Hulsea vestita ssp. inyoensis (Inyo hulsea, pumice alpinegold) - Inyo Mountains, Death Valley N. P. ranges, and others in Inyo/Mono Counties & W. Nevada. Hulsea vestita ssp. parryi (Parry's alpinegold) - San Bernardino Mountains, other Transverse & Peninsular ranges, Sierras. Hulsea vestita ssp. pygmaea (pygmy alpinegold) - San Bernardino Mnts, Southern Sierras. Hulsea vestita ssp. vestita (pumice alpinegold) - Sierras, east Transverse ranges.

Hydrocotyle ranunculoides, known commonly as water pennywort or floating pennywort is an aquatic plant in the Apiaceae. It is native to North and South America and parts of Africa. In the UK it is an invasive alien species which is currently spreading in waterways in England and Wales. It is also a weed in Australia. On the other hand, it is a threatened species in parts of its native range in the United States.

Hydrocotyle umbellata, is an aquatic plant that thrives in wet, sandy habitat. Its English common name is manyflower marsh pennywort. It is native to North America and parts of South America. It can also be found growing as an introduced species and sometimes a noxious weed on other continents. It is an edible weed that can be used in salads or as a pot herb.

Hydrocotyle verticillata, also known as whorled pennywort, whorled marshpennywort or shield pennywort, is a flowering plant found in South and North America and the West Indies. The creeping plants with unusual leaves give it its common names. It grows in places that are marshy, boggy, and wet. Hydrocotyle verticillata is used in aquaria, where it is undemanding but prefers a good substrate, and at least moderate light. It benefits from additional carbon dioxide. It is widely used as a foreground plant.