Saw Toothed Goldenbush (Hazardia squarrosa var. grindelioides) is a native sub-shrub in the Asteraceae (Sunflower) family that grows in southern and central California. It is found along the coast, in the foothills, valleys, and coastal mountains from Monterey County to northern Baja at elevations from 300-4300 feet. It is also commonly found along roadsides, trail edges, and other disturbed places. The flower head consists of only disc flowers. The flowers have great color and a long bloom time. There are two other recognized varieties of this species that differ primarily in leaf shape. This plant is good for "wild" gardens and for restoration projects.

The daisylike plant Helenium bigelovii is known as Bigelow's sneezeweed. It is a plant of meadows and marshes that bears flowers that are usually bright yellow in color. It grows in moist areas. It is found at moderate elevation in the foothills and low mountains of California. Cultivars are raised as ornamentals.

Helenium puberulum is a species of flowering plant in the daisy family known by the common name rosilla. It is native to California and Baja California, where it can be found in moist habitats such as riverbanks and meadows. This is an annual or perennial herb varying in size and shape from a low stem with few branches to an erect, spindly stem nearing 1.5 meters tall. Most of the leaves are on the lower part of the plant, with the upper occupied by naked peduncles bearing flower clusters of several daisylike flower heads. Each head is mainly a spherical bunch of disc florets which are yellow when new and darken with age. Some heads also have a few to many yellow ray florets. The fruit is a hairy achene one to two millimeters long.

Helianthella californica is a species of flowering plant in the sunflower family known by the common name California helianthella. This wildflower is native to the mountains of California and Oregon. It is a taprooted perennial herb producing erect stems up to about 60 centimeters tall. The many lance-shaped leaves are up to 4 centimeters wide and smooth or slightly toothed along the edges. The flower cluster holds one or more sunflower-like flower heads. Each head has a center of golden disc florets with purple or reddish parts, and a fringe of yellow ray florets one or two centimeters long.

The perennial herb Helianthella castanea is a rare plant endemic to California, and is only found in the San Francisco Bay Area, mostly in and around Mount Diablo State Park. Its common names include Mount Diablo helianthella, Mount Diablo sunflower, and Diablo rockrose. A member of the daisy and sunflower family, the flowers are bright yellow and daisy-like, with ridged petals. The plant grows in clumps of green foliage and sends up flowers on long stems.

Sunflower (Helianthus annuus) is a robust annual in the Asteraceae (sunflower) family, widely seen across California. Often found in disturbed areas like road shoulders, edges of farm fields, and vacant lots, it is also a striking addition to gardens when given ample space, direct sun, and regular watering.

This plant produces stout stalks topped with large, cheerful flower heads. The flower head is a composite of numerous small florets, with outer ray florets in shades of yellow, maroon, orange, or other colors, and inner brown disc florets that mature into seeds. Horticultural varieties like 'Autumn Beauty' offer additional color variations.

Sunflowers are excellent habitat plants, offering nectar and pollen for a wide array of bees and butterflies. Their seeds are a valuable food source for birds, making them a wonderful choice for wildlife-friendly gardens.

Tolerates almost any soil type. RsABG introduction.

Helianthus bolanderi is a species of sunflower known by the common names Serpentine Sunflower and Bolander's Sunflower. It is native to California and Oregon, where it grows mainly in mountainous areas, often in serpentine soils. This wild sunflower is an erect annual reaching heights over 3 feet. It has a hairy, rough stem with leaves lance- or oval-shaped, usually pointed, sometimes serrated along the edges, and 1.2 to 6 inches long. The flower cluster holds one or more flower heads, and each plant may have many flower clusters growing along the full length of the stem. The flower head has a cup of long, pointed phyllaries holding an array of bright yellow ray florets each less than an inch long around a center of yellow to dark purple or reddish disc florets.

Helianthus californicus is a species of sunflower known by the common name California sunflower. It is native to California and Baja California, where it grows in many types of habitat. This wild sunflower is an erect perennial growing from a network of tough, woody roots with small rhizomes. It is a sprawling, gangly plant, sending a thin stem to heights between one and three meters or more. The lance-shaped leaves may be 20 centimeters long and are smooth or slightly toothed along the edges. The flower cluster holds several flower heads. Each head is supported by a base covered in long, pointed phyllaries that bend back as the head ages and develops fruit. The flower head has a fringe of golden yellow ray florets, each two or three centimeters long, and a center filled with curly yellow and brown disc florets. The achene is about half a centimeter long.

Slender Sunflower is a species in the Asteraceae (Sunflower) family that is native to central and southern California and Baja California, where it is a member of the chaparral and yellow pine forest habitats. This is a perennial herb growing from a thick taproot to heights anywhere between one half and two meters. The lance-shaped, pointed leaves are smooth-edged or slightly toothed and up to about 11 centimeters long. The long, slender stems and foliage are covered in rough hairs. The flower cluster bears flower heads with an array of short, hairy phyllaries behind a thick center of yellow to red-brown disc florets. The golden ray florets around the edge are one to three centimeters long. Grows well in chaparral and yellow pine forest habitats.

Heliomeris multiflora is a North American species of flowering plants in the sunflower family called the Showy goldeneye. It grows in Mexico and the western United States from Montana to Jalisco. Heliomeris multiflora is an annual herb up to 15 cm (5. 9 in) tall, with a large taproot. Leaves are up to 16 cm (6. 3 in) long, with hairs along the edges. One plant can produce 25 or more yellow flower heads, each head with 12-14 ray flowers surrounding 50 or more tiny disc flowers.

Seaside heliotrope (Heliotropium curassavicum) is an attractive flowering perennial that's also called salt heliotrope. Seaside heliotrope grows throughout the US. In California, it is commonly found near water sources, in alkaline or saline soils. This plant has a creeping growth habit, although it can grow to around 1.5 ft in height. The leaves and stems are thick and fleshy. The small, bell-shaped flowers grow along curved stalks and are white with yellow centers that turn purple as they mature.

Seaside heliotrope is not generally known for its fragrance, unlike other varieties of heliotrope which are famous for their sweet, almond-like scent. But the blooms are attractive to bees and butterflies, making it a worthwhile addition to the pollinator garden. It grows in full or partial sun in a variety of soil types and does best with occasional supplemental water. It can also be a container garden plant.

Hemizonia congesta is a species of flowering plant in the daisy family known by the common name hayfield tarweed. It is native to California and Oregon, where it is a common member of the flora in a number of habitats, particularly grasslands and fields. This is a spindly, thin-stemmed annual herb growing erect to 10 to 80 centimeters in height. Like other tarweeds the stem and foliage are hairy and have an odor reminiscent of tar. Most of the long, narrow, pointed leaves are located on the lower portion of the stem below the branching. The flower clusters are covered in hairy hairs and hold daisylike flower heads. Each head has a center of yellowish dark-tipped disc florets and a fringe of bright yellow to white ray florets, often with purplish striping on the undersides. The ray florets are toothed or lobed on the tips, with the middle tooth thinner than the others. There are many subspecies which can vary in appearance.

Hayfield Tarweed (Hemizonia congesta ssp. congesta) is a rare native annual herb that grows in northern, southern and central California. It tends to grow in open grassy places, at elevations from 0-1000 feet.

Hemizonia congesta ssp. lutescens is a common native annual herb that grows in Central and Northern California, primarily in the North Coast and North Coast Range regions. It tends to grow in open grassy places, at elevations from 0-4600 feet.

Hayfield Tarweed (Hemizonia congesta ssp. luzulifolia) is a common native annual herb that grows in northern, southern and central California. It tends to grow in open places, at elevations from 0-3000 feet.

Hesperocallis is a genus of flowering plants that includes a single species, Hesperocallis undulata, the desert lily, found in the desert areas of the southwest of North America. Hesperocallis has traditionally been classified in Liliaceae but until recently its relationships have been unclear. Other classifications have included it in Hemerocallidaceae or Funkiaceae. In 1972, Hamilton Traub created the family Hesperocallidaceae with Hesperocallis as the sole included genus. The APG II system includes it in the family Asparagaceae in the order Asparagales in the monocots clade but allows for the optional segregation of Hesperocallidaceae as a monophyletic family when several other families are likewise segregated. Recent molecular systematic studies have confirmed a close relationship with Agave and its inclusion in family Agavaceae has been recommended (Pires et al. 2004).

Hesperochiron is a small genus of plants in the waterleaf family containing two species native to western North America. These are thick-rooted perennial herbs growing in squat patches at ground level and producing bluish-white flowers with yellow throats. They grow in wet areas such as seepy meadows. The species are generally similar in appearance, with oblong green leaves up to 7 or 8 centimeters long and 2 to 3 wide, often coated with tiny hairs. Hesperochiron nanus, the California hesperochiron, produces slightly larger flowers than the dwarf hesperochiron, H. pumilus.

Hesperochiron is a small genus of plants in the waterleaf family containing two species native to western North America. These are thick-rooted perennial herbs growing in squat patches at ground level and producing bluish-white flowers with yellow throats. They grow in wet areas such as seepy meadows. The species are generally similar in appearance, with oblong green leaves up to 7 or 8 centimeters long and 2 to 3 wide, often coated with tiny hairs. Hesperochiron californicus, the California hesperochiron, produces slightly larger flowers than the dwarf hesperochiron, H. pumilus.

Cupressus bakeri, the Modoc Cypress, Siskiyou Cypress or Baker Cypress, is a species of cypress native to the United States, in a restricted area of northern California (Siskiyou, Modoc, Shasta and Plumas Counties) and southwest Oregon (very localized in Josephine and Jackson Counties). It is usually found in small, scattered populations, not in large forests, at altitudes of 900-2000 meter. It is a medium-sized evergreen tree with a conic crown, growing to heights of 10-25 meter (exceptionally to 39 meter), and a trunk diameter of up to 0.5 meter (exceptionally to 1 meter). The foliage grows in sparse, usually pendulous sprays, varying from dull gray-green to 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, 10-25 millimeter long, with 6 or 8 (rarely 4 or 10) scales, green to brown at first, maturing gray or gray-brown about 20-24 months after pollination. The cones often remain closed for several 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.

Tecate Cypress (Herpericyparis forbesii) is a species of cypress native to Southern California and Mexico. This is a relict species from a time when southern California's climate was cooler and wetter. It survives in a few, isolated locations in Los Angeles, Orange, Riverside and San Diego Counties, as well as northern Baja. It depends on intermittent fire for reproduction, but too frequent fires kill seedlings and threaten the survival of the species.

The foliage is bright green with reddish bark. Young trees are pyramidal in shape, becoming more rounded or contorted with age. It is very drought adapted; excessive supplemental water will make it floppy. In recent years, Tecate Cypress has become a fairly popular small tree for Southern California gardens. It makes a great specimen tree for larger landscapes, remaining tight and symmetrical.

The northernmost stand, comprising a very large area on the upper limits of Coal Canyon and Sierra Peak in Orange County, California, burned in a 2006 wildfire. Very few mature trees survived, but hundreds, if not thousands, of new plants are appearing as regeneration. Another devastating wildfire before seedlings are able to reach cone-producing age (which can be quite old for this species), could easily extirpate this stand.

Some refer to Tecate Cypress as a variety of Guadalupe Cypress (Cupressus guadalupensis), which occurs on Guadalupe Island, though that island is well over 250 miles from any Tecate Cypress stand. Aside from the ease of surmising that Tecate Cypress is genetically different from Guadalupe Cypress due to the two species being separated by ocean waters, molecular testing has shown the latter to be slightly more closely related to Cuyamaca Cypress (Hesperocyparis stephensonii).

Moreover, Guadalupe Cypress, when mature, makes a much taller and more massive tree than Tecate Cypress. Tecate Cypress has very green foliage, while Guadalupe Cypress has waxy pale, somewhat blueish tinted foliage. Finally, though cones of Tecate Cypress will not open without heat (unlike any other California native Cypress), those of Guadalupe Cypress will open without fire.

Cupressus goveniana, now reclassified as Hesperocyparis goveniana, with the common names Californian cypress and Gowen cypress, is a species of cypress, that is endemic to California. The tree is endemic to the Monterey Peninsula in coastal Monterey County, located on the Central Coast of California, in the Western United States. The tree is found in small, scattered populations, and not in large forests of its species. Hesperocyparis goveniana occurs with Hesperocyparis macrocarpa (Monterey cypress), in the two groves where the Monterey cypress is known to occur naturally, in Monterey County. It is on the IUCN Red List of endangered species. Hesperocyparis goveniana is an evergreen tree with a conic to ovoid-conic crown, very variable in size, with mature trees of under 1 m (3 ft 3 in) on some sites, to 50 m (160 ft) tall in ideal conditions. The foliage grows in dense sprays, dark green to somewhat yellow-green in color. The leaves are scale-like, 2-5 mm (0. 08-0. 20 in) long, and produced on rounded (not flattened) shoots. The seed cones are globose to oblong, 11-22 mm (0. 43-0. 87 in) long, with 6 to 10 scales, green at first, maturing brown 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 mm (0. 12-0. 20 in) long, and release pollen in February/March. Typically, cones of H. goveniana are smaller than those of H. macrocarpa. Taxonomy. The varieties or subspecies, formerly included under Cupressus goveniana by some botanists, include:Cupressus goveniana var. goveniana - reclassified as Hesperocyparis goveniana. Monterey County, strictly coastal, within 3 km (1. 9 mi) of the coast and below 200 m (660 ft) altitude. Foliage dark green, not rough, with leaf tips not spreading; cones globose. Cupressus goveniana var. pigmaea, reclassified as Hesperocyparis pygmaea - Mendocino cypress (vulnerable species). Mendocino and Sonoma counties, coastal, within 10 km (6. 2 mi) of the coast and below 500 m (1,600 ft) altitude. Cupressus goveniana var. abramsiana, reclassified as Hesperocyparis abramsiana - Santa Cruz cypress (endangered species). Santa Cruz and San Mateo counties, in the Santa Cruz Mountains 10-20 km (6. 2-12. 4 mi) inland and at 300-760 m (980-2,490 ft) altitude. With yellow-green foliage slightly rough-textured from the acute and slightly spreading leaf tips; cones often oval.

Cupressus macnabiana (McNab Cypress or Shasta Cypress) is a species of cypress endemic to northern California. It is one of the most widely distributed of all the native California cypresses, found growing in chaparral, oak woodlands and coniferous woodlands along the inner northern Coast Ranges and the foothills of the northern Sierra Nevada. It is an evergreen shrub or small tree, 3-12 meter (rarely to 17 meter) tall, with a spreading crown that is often broader than it is tall. The foliage is produced in dense, short flat sprays (unlike most other California cypresses, which do not have flattened sprays), bright waxy pale gray-green in color, with a strong spicy-resinous scent. The leaves are scale-like, 1-2 millimeter long with an acute tip, and a conspicuous white resin gland on the center of the leaf. Young seedlings produce needle-like leaves up to 10 millimeter long in their first year.

Monterey Cypress (Hesperocyparis macrocarpa) is a handsome coniferous tree that's native to California's central coast. Although it's often planted as an ornamental landscape tree in California and elsewhere, just two small populations of Monterey Cypress trees remain in the wild. These remaining trees are very old and grow in protected areas.

Monterey Cypress can grow up to 82 ft in height, making it one of the tallest cypress trees. Young trees have an upright growth habit, while mature trees have a broad sculptural appearance. The trees in the remaining coastal stands are known for their distinctive windswept look. Monterey Cypress has fragrant, dark green needles and textured bark. A single tree produces male and female cones.

Because it can grow quite large, Monterey Cypress needs a large planting area. It does best in cool, moist coastal areas but can grow further inland with additional water. It can tolerate acidic, nutrient-poor soil as long as it's well-draining.

One of the few native plants that the California Invasive Plant Council has determined is invasive in regions outside its natural range. It has invaded coastal prairie, desert scrub, and riparian areas.

Grows best in sandy, coarse-grained or other fast draining soil. Selected for the garden.

Tolerates almost any soil type. Selected for the garden.

Cupressus sargentii is a species of conifer in the Cupressaceae family known by the common name Sargent's cypress. It is endemic to California, where it is known from Mendocino county southwards to Santa Barbara county. This taxon is limited to the Coast Range mountains. Like Mcnab Cypress, it is one of the most widespread of the California Cypresses. It grows in forests with other conifers, as well as chaparral and other local mountain habitat, usually in pure stands on serpentine soils. It generally grows 10 to 15 meters tall, but it is known to exceed 22 meters. On Carson Ridge in Marin County, as well as Hood Mountain in Sonoma County, the species comprises a pygmy forest of trees which do not attain heights greater than 8-12 feet due to high serpentine concentrations in the soil.

Chaparral yucca (Hesperoyucca whipplei)  is a striking, drought-adapted plant known for its dramatic presence year-round and spectacular flowering display. The plant begins as a large, rounded rosette of silver-green, spiky leaves. When mature — typically after 5 to 6 years — it sends up an impressive flower spike that grows 10 to 15 feet tall in just a few weeks. The towering spike is covered with hundreds of bell-shaped flowers, ranging from white to pale purple, creating a stunning visual impact in the landscape.

Native to California and parts of Baja California, chaparral yucca thrives in chaparral, coastal sage scrub, and oak woodland plant communities at elevations of 950 to 8,200 feet. It is well-adapted to rocky, dry soils and plays an important ecological role in its native habitat.

Chaparral yucca forms an exclusive pollinator relationship with the California Yucca Moth (Tegeticula maculata), making it a fascinating example of co-evolution. The moth is the plant's sole pollinator and relies on the yucca for its life cycle. The moth collects pollen from the flowers and deposits it on another flower’s stigma while laying its eggs inside the ovary. The developing moth larvae feed on some of the yucca seeds, while others are left to grow and disperse.

After the flowers are pollinated, the yucca plant dies, a process known as monocarpic reproduction. However, the dried flower stalk often remains standing for several years, creating a natural sculpture in the landscape. New plants emerge from seeds or from offsets at the plant’s base.

Chaparral yucca is also known by several common names, including our lord’s candle, Spanish bayonet, Quixote yucca, common yucca, and foothill yucca. Despite its beauty, it is reportedly difficult to grow outside its native range. However, when planted in the right conditions, it provides a bold accent in native gardens, particularly when combined with rocks or other drought-adapted plants. Care should be taken to place the plant away from pathways, as its sharply pointed leaves can cause injury.

This iconic plant is a resilient symbol of California’s rugged chaparral landscapes, offering both ecological value and ornamental appeal.

Toyon (Heteromeles arbutifolia), also known as Christmas Berry, is an evergreen shrub in the Rose family (Rosaceae). In the summer it produces bunches of fragrant white flowers. In the winter it develops vibrant clusters of scarlet berries. The flowers attract butterflies and other pollinators. The berries are eaten by many birds, including Mockingbirds, American Robins, and Cedar Waxwings. Mammals including coyotes and bears also eat and disperse the berries. For humans, the berries are edible after cooking, or drying and crushing, in order to break down the small amounts of cyanogenic glycosides. Indigenous People use the berries to make cider, and a granular sugar. 

Toyon is a prominent component of the Coastal Sage Scrub plant community, and is a part of drought-adapted Chaparral, Mixed Evergreen Forest and Oak Woodland habitats. Toyon are beautiful plants and easy to grow. If properly situated, they can grow very quickly, up to 10 feet in three years. They like sun or part shade, though they tend to do better in part shade in the southern, drier part of their geographic range. They can handle a wide variety of soils, including clay, sand and serpentine. They are an excellent hedge plant.

Horticultural selection from Heteromeles arbutifolia. A keystone shrub in the native landscape, Toyon (also known as Christmas Berry), is the common name for Heteromeles arbutifolia. Toyon is known as a dependable long lived shrub and valued for the visual appeal of its small white flowers in summer, persistent berries in the winter and evergreen foliage. A cultivar of Heteromeles arbutifolia var. cerina, 'Davis Gold' has striking yellow berries instead of the typical red, and has been noted as having improved resistance to disease. Toyons are very flexible when it comes to light exposure, growing best in sun but tolerating almost full shade. A classic wildlife attractor, birds in particular love to eat the golden berries that linger on the plant. 'Davis Gold' toyon has leathery serrated leaves 2 -4" long and grows well in sandy soils and on slopes with dry, well drained soils. 'Davis Gold' is excellent as a screening plant, hedge, or multi-trunk small tree, reaching a typical height and width of about 6 - 1 '; given ideal conditions and enough time it can grow to 15' or more.This is a selection introduced by UC Davis and it tolerates almost any soil type. Selected for the garden.

Heterotheca grandiflora is a species of flowering plant in the Asteraceae (Sunflower) family known by the common name Telegraph Weed. It is native to the southwestern United States and northern Mexico, but it can be found in other areas as an introduced species, such as Hawaii. In California it is widespread from Butte County southward. It is a pioneer species and roadside weed even where it is native. This is a tall, bristly, hairy plant exceeding a meter in height and densely foliated in hairy to spiny toothed or lobed leaves. Leaves are smaller and more widely spaced toward the top of the stem, which is occupied by an flower cluster of bright yellow daisylike flower heads. The disc and ray florets drop away to leave a spherical head of achenes, each with a long white pappus. This plant is rarely used in the garden but is a useful for restoration projects.

Heterotheca sessiliflora is a species of flowering plant in the Asteraceae (Sunflower) family known by the common name False Goldenaster. It is native to California and Baja California, where it grows primarily along the coast, in the foothills and mountains, in many types of habitat. This is a perennial herb which is quite variable in appearance. There are four recognized subspecies which vary in morphology and geographic range. Depending on subspecies and location, it may be a small clumping or mat-forming plant or grow tall stems to heights exceeding a meter. It may appear as an annual or perennial herb. It is coated in small bristles or long woolly hairs and it is hairy, particularly around the flower cluster. The flower head contains long yellowish disc florets and the edge is fringed with yellow ray florets. Its most outstanding feature is nearly year-round flowering.

Bolander's Goldenaster (Heterotheca sessiliflora ssp. bolanderi) is a native perennial herb that grows in Central and Northern California, primarily in the North Coast and Central Coast regions. It tends to grow in dunes and grassy places, at elevations from 0-800 feet.

Tolerates almost any soil type. Prefers sun in coastal sites, and sun or part shade in inland sites. Selected for the garden.

Bristly Goldenaster (Heterotheca sessiliflora ssp. echioides) is a native perennial herb that grows in southern and central California. It tends to grow in dunes and grassy places, at elevations from 0-3600 feet.

Camphor Weed (Heterotheca psammophila) is a uncommon native annual or perennial herb that grows in Southern California, primarily in the South Coast and Sonoran Desert regions. It tends to grow in disturbed or recently burned sandy places, at elevations from 0-1000 feet.

Hairy False Goldenaster (Heterotheca villosa) is a native perennial herb that grows in northern, southern and central California. It is moderately fast growing and short-lived. It grows in an upright form to a height of 3 feet, with active growth during the spring and summer. Flowers are yellow and striking, and bloom in the mid summer. Leaves are gray-green and deciduous. It tends to grow in crevices, at elevations from 1300-10200 feet.

Grows best in sandy, coarse-grained or other fast draining soil. Prefers sun in coastal sites, and sun or part shade in inland sites. Selected for the garden.

Heuchera abramsii is a rare species of flowering plant in the saxifrage family known by the common names San Gabriel alumroot and Abrams' alumroot. It is endemic to the San Gabriel Mountains of southern California, where it grows on rocky slopes.

Island alum root (Heuchera maxima) is a perennial flowering plant in the saxifrage family. In gardens it is valued as a groundcover for both its foliage and its flowers that hummingbirds love. The  rounded green leaves grow in a broad patch and remain low. In winter to spring, tiny white-pink flowers bloom in frothy clusters towards the top of tall erect stems that rise above the leaves and may reach to about 2 feet.  

This plant performs best in coastal gardens, where it can take full sun to part shade. In inland gardens, it may require full shade and additional water. It looks good in woodland gardens.  It is adaptable to different types of soil but prefers sandy/rocky soil with good drainage. 

In the wild, this plant is endemic to three of the eight Channel Islands of California, where it grows on cliffs and canyon walls. It is rare due to its limited distribution. 

Heuchera merriamii is a species of flowering plant in the saxifrage family known by the common name Merriam's alumroot. It is native to the Klamath Mountains of southern Oregon and northern California, where it grows on the rocky slopes. This is a rhizomatous perennial herb producing a patch of leaves which are rounded and have five to seven lobes along the edges. It produces an erect inflorescence up to about 23 centimeters tall with sparse clusters of pinkish, yellow, or cream flowers. The inflorescence is covered in glandular hairs. Each flower has small spoon-shaped petals and protruding stamens.

Hibiscus denudatus (common names: Paleface, Rock Hibiscus) is a perennial shrub of the mallow family, Malvaceae. It is in the rosemallow genus, Hibiscus. It is found in the southwest of North America in the southwestern United States and northern Mexico in the states of extreme southeast California, southern Nevada, southern Arizona and New Mexico, southwest Texas, Baja California-north, Sonora, Chihuahua, and Coahuila. It can be found in the Colorado and Sonoran Deserts, and in the east to the Chihuahuan Desert.

Hibiscus lasiocarpos (also, H. lasiocarpus orth. var. ) is a species of hibiscus known by the common name hairy-fruited hibiscus. It is also one of several hibiscus called rosemallow. It is native to much of the southeastern United States, as well as parts of California and northern Mexico. It is a large, bushy perennial herb with sprawling stems reaching one to two meters long. The leaves are heart-shaped, toothed, and pointed, and generally between 6 and 10 centimeters long. The inflorescence holds large showy, solitary flowers. Each flower has a cup of partly fused sepals beneath a layer of slender bracts. These may be covered in hairs or woolly fibers. The flower's large petals may be up to 10 centimeters long and are generally bright white with red bases. The stamen tube and anthers are white or cream. The fruit is a capsule 2. 5-3 centimeters long containing spherical seeds.

Rose Mallow (Hibiscus lasiocarpus) is a rare native perennial herb that grows in Northern, Southern and Central California, primarily in the Sacramento Valley and San Joaquin Valley regions. It tends to grow in marshes and wet places, at elevations from - feet.

Hieracium argutum is a species of flowering plant in the aster family known by the common name southern hawkweed. It is endemic to California, where it can be found in coastal and inland hills and mountains, often in oak woodland and pine forest habitat. Hieracium argutum is a perennial herb producing a mostly erect stem which is very hairy on the lower part and becomes nearly hairless toward the tip. The plant grows 60 centimeters to one meter tall. The deeply toothed leaves are covered in long hairs. The largest leaves at the base of the stem may reach 16 centimeters. There may be shorter leaves on the lower part of the stem and there are few or none on the upper part. The inflorescence is a wide open array of many flower heads, each up to about a centimeter wide. The flower head is lined with hairy, often glandular phyllaries and filled with many yellow ray florets and no disc florets. The fruit is a small, dark cylindrical achene topped with a pappus of brown bristles.

Hieracium bolanderi or Bolander's hawkweed is a North American plant species in the dandelion tribe within the sunflower family. It is found primarily in the mountains of western Oregon and northern California in the United States, although there are reports of the species farther south in the San Bernardino Mountains in southern California and also in Baja California in Mexico. Hieracium bolanderi is an herb up to 60 cm (2. 0 ft) tall, with leaves mostly in a rosette at the bottom. Leaves are up to 95 mm (3. 7 in) long, with no teeth on the edges. One stalk will produce 3-40 flower heads in a flat-topped array. Each head has 6-12 yellow ray flowers but no disc flowers.

Hieracium scouleri is a North American species of hawkweed in the dandelion tribe within the sunflower family. It is known by the common name Scouler's woollyweed. It is native to the United States and Canada from British Columbia and Alberta south as far as northern California and Utah. Hieracium scouleri grows in a variety of mountainous habitats. It produces a basal rosette of long, narrow leaves 10-20 centimetres (3. 9-7. 9 in) long, which are generally hairy to bristly. The plant produces an erect stem 30-70 centimetres (12-28 in) tall which bears the inflorescence. Each flower head has large, curling bracts with glandular hairs or bristles, long, bright yellow ray florets but no ray florets. The achene is about 3 millimetres (0. 12 in) long.

Pleuraphis jamesii (syn. Hilaria jamesii) is a species of grass known by the common name James' galleta. It is native to the southwestern United States, where it is widespread in scrub, woodland, grassland, and plateau habitat. It is tolerant of arid environments such as desert floors. It is a rhizomatous perennial grass producing bunches of erect stems approximately one millimeter wide and up to about 60 centimeters in maximum height. The woody rhizome is shallow, spreading just under the soil surface, but it may reach 6 feet in length and when dense helps the grass form a sod. The flower cluster is a series of hairy, rectangular spikelets. The grass produces relatively little viable seed and spreads mostly via its rhizome.

Pleuraphis rigida (syn. Hilaria rigida) is a species of grass known by the common name big galleta. It is native to the southwestern United States and northern Mexico, where it is widespread in scrub, woodland, grassland, and plateau habitat. It is tolerant of arid environments such as desert floors, and it is the dominant grass in some desert scrub regions. It is a bushy, clumping perennial grass producing coarse, erect stems reaching a meter in maximum height. The clumpy form of the grass helps it stabilize loose and blowing sand when it grows in desert dune habitat. The stems have nodes which are lined with long, sometimes curly hairs. The flower cluster is a series of hairy or brushlike rectangular spikelets. The grass produces relatively little viable seed and spreads mostly via its tillers and sometimes via rhizome. This grass acts as a nurse plant to seedlings of other species, such as cholla and barrel cactus, in turn receiving protection from herbivory by growing next to the spiny plants.

Hoita macrostachya is a species of legume known by the common name large leatherroot. It is native to California and Baja California where it can be found in moist areas of a number of habitat types. This is a hairy, hairy perennial herb producing a tall, branching stem approaching two meters in maximum height. The sparse, widely spaced leaves are each made up of three leaflets up to 10 centimeters long each attached to a long petiole. The leaflet blades are hairy. The plant produces many clublike raceme flower clusters on sturdy stalks from the stem. The flower cluster contains many purplish pealike flowers. The fruit is a hairy, veiny brown legume pod under a centimeter long containing a kidney-shaped seed.

Hoita orbicularis is a species of legume known by the common name roundleaf leatherroot. It is endemic to California, where it is relatively widespread throughout the state's mountain ranges, growing most often in moist habitat. It is a perennial herb growing prostrate or nearly so at ground level with large leaves each made up of three round leaflets up to 11 centimeters long each. The herbage is hairy and often hairy. The flower cluster is an erect raceme which may be up to 35 centimeters long. Each of the many flowers is one or two centimeters long, pealike, and generally a shade of light to medium purple in color. The fruit is a hairy, veiny legume pod just under a centimeter long.

Holocarpha heermannii is a species of flowering plant in the aster family known by the common name Heermann's tarweed. It is endemic to California, where it grows in the hills, mountains, and valleys of the central part of the state. It is most common in the eastern San Francisco Bay Area and the southern end of the Sierra Nevada foothills. This is an annual herb growing mostly erect from 20 centimeters to over one meter in height. The stem is densely hairy and coated in short and long hairs. The leaves are up to 10 centimeters long near the base of the plant and those along the stem are smaller. The flower cluster is a spreading array of branches bearing clusters of flower heads. Each flower head is lined with phyllaries which are coated in large bulbous resin glands. They are hairy and sticky in texture. The head contains many yellow disc florets surrounded by three to 10 golden yellow ray florets. The ray and fertile disc florets produce achenes of different shapes.

Holocarpha virgata is a species of flowering plant in the aster family known by the common name yellowflower tarweed. It is endemic to California, where it is most common in the Central Valley and adjacent foothills to the east and west. There is also a disjunct population near San Diego. This is an annual herb producing an erect stem 20 centimeters to over one meter tall. It has many branches and is lined with oily glands and hairs. The linear leaves are up to 15 centimeters long near the base of the plant and those along the stem are much smaller. The flower cluster is made up of several short branches lined densely in small, thick, green leafs. The leafs are just a few millimeters long and are tipped with glands. At the ends of the branches are flower heads, each lined with phyllaries which are covered in knobby resin glands. The head contains many disc florets which are yellow with black or purplish anthers. The head has a fringe of several yellow ray florets which often have lobed tips.

Narrow Tarplant (Holocarpha virgata ssp. virgata) is a native annual herb that grows in central and northern California. It tends to grow in grassy places, at elevations from 0-2600 feet.

Desert Ocean Spray (Holodiscus microphyllus var. glabrescens) is a native shrub that grows in central and northern California. It tends to grow in rocky places and outcrops, at elevations from 2000-9500 feet.

Little Leaf Creambush (Holodiscus microphyllus var. microphyllus) is a native shrub that grows in northern, southern and central California. It tends to grow in rocky places and outcrops, at elevations from 3900-13100 feet.

Hooveria parviflora is a species of perennial herb in the lily family known by the common name smallflower soap plant. It is a monocot native to coastal southern California and Baja California, where it is a member of the coastal sage scrub flora. This perennial wildflower grows from a dark-coated bulb several centimeters wide. The basal leaves have wavy edges. The flower cluster may reach 90 centimeters tall and is made up of many dark-veined white or pinkish flowers. Each flower has six petals just under a centimeter long which are spread open for only one day. The six stamens are tipped with yellow anthers. The fruit is a capsule a few millimeters long.

Hordeum brachyantherum is a species of barley known by the common name meadow barley. It is native to western North America from Alaska to northern Mexico, far eastern Russia, and parts of eastern North America. It can be found in other parts of the world as an introduced species. This is a tufting perennial grass approaching a meter in maximum height. It produces compact, narrow flower clusters 8 to 10 centimeters long and purplish in color. Like other barleys the spikelets come in triplets. It has two small, often sterile lateral spikelets on pedicels and a larger, fertile central spikelet lacking a pedicel.

Hordeum depressum is a species of barley known by the common names low barley and dwarf barley. It is native to the western United States from Idaho to California, where it can be found in moist habitats such as vernal pools. This is a small annual grass forming petite patches of thin, hairy leaves and erect stems to half a meter in maximum height. The green or reddish green flower cluster is 2 to 6 centimeters long and about half a centimeter wide. Like other barleys the spikelets come in triplets. There is a large fertile central spikelet about a centimeter long and two smaller, often sterile spikelets on pedicels, each 3 to 5 millimeters long.