Artemisia ludoviciana is a species of sagebrush known by several common names, including silver wormwood, white sagebrush, and gray sagewort. It is native to North America where it is widespread coast to coast, but many subspecies are found only in the western United States. This is a rhizomatous perennial herb growing to heights between 30 centimeters and one meter. The stems bear linear leaves up to 11 centimeters long. The stems and foliage are covered in woolly gray or white hairs. The top of the stem is occupied by a narrow flower cluster of many nodding flower heads. Each small head is a cup of hairy phyllaries surrounding a center of yellowish disc florets and is about half a centimeter wide. The fruit is a minute achene. This plant was used by many Native American groups for a variety of medicinal, veterinary, and ceremonial purposes.

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

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

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

White Mugwort (Artemisia ludoviciana ssp. albula) is a common native perennial herb that grows in southern and central California. It tends to grow in dry and sandy and rocky places, at elevations from 0-4600 feet.

White Sagebrush (Artemisia ludoviciana ssp. ludoviciana) is a common native perennial herb that grows in northern, southern and central California. It tends to grow in dry and sandy and rocky places, at elevations from 0-8500 feet.

Artemisia michauxiana is a species of wormwood known by the common names Michaux's wormwood and lemon sagewort. It is native to western North America from Yukon to California to Colorado, where it grows in mountain talus habitats in subalpine to alpine climates. This is a rhizomatous perennial herb with green, lemon-scented foliage. The plant grows up to a meter tall with several erect branches. The leaves are divided into many narrow segments which are hairless or lightly hairy and bear yellowish resin glands. The flower cluster is a spike up to 15 centimeters long full of clusters of small flower heads. Each head is lined with rough purplish green, hairy phyllaries and generally contains pale pistillate and disc florets. The fruit is a tiny hairless achene.

Artemisia nesiotica is a species of sagebrush known by the common name island sagebrush. It is endemic to the three of the eight Channel Islands of California. This is a small shrub growing up to about half a meter tall and generally rounded in shape. It produces several thin, upright stems from a woody base. The foliage is made up of woolly leaves divided into many thin, flat, threadlike segments. The flower cluster is a narrow cluster of several flower heads. The fruit is a tiny resinous achene with a pappus of hairs.

Artemisia norvegica is a species of flowering plant in the aster family known by the common names alpine sagewort, boreal sagewort, mountain sagewort, Norwegian mugwort, arctic wormwood, and spruce wormwood. It is found in cold locations in Eurasia (Scotland, Scandinavia, Ural Mountains of Russia) and high altitudes and high latitudes in North America (Nunavut, Yukon, Alaska, British Columbia, Alberta, Washington, Montana, Wyoming, Wyoming, California). Artemisia norvegica is a perennial subshrub growing 20 to 60 centimetres (7. 9 to 23. 6 inches) tall with erect stems growing from a caudex and taproot. Most of the leaves are located low on the stems and are 2 to 20 centimetres (0. 79 to 7. 87 inches) long. The nodding inflorescence bears flower heads containing ray and disc florets. The ray florets are female with no functioning male parts and the disc florets at the center are bisexual. The plant reproduces by seed and may spread vegetatively by sending out stolons. The seeds are dispersed on the wind.

Artemisia nova is a species of sagebrush known by the common name black sagebrush. It is native to the western United States from California to Montana to New Mexico, where it grows in forest, woodland, and grassland habitats. It is "one of the most common shrubs in the western United States". Identification is sometimes difficult, because this species is similar in appearance to little sagebrush, Artemisia arbuscula, and it easily hybridizes with big sagebrush, Artemisia tridentata, when the it grows in the same area, leading to intermediate forms. Also, A. nova has two main morphological forms, a darker, easily recognized form, and a less common light gray-green colored variant which closely resembles other sagebrush species. In general, this is a small, erect shrub producing upright stems branched off a central trunklike base. It is usually no taller than 20 to 30 centimeters but it has been known to exceed 70 centimeters in height. The aromatic leaves are green, short, narrow, and sometimes toothed at the tip. This species can sometimes be distinguished from its similar-looking relatives by black-tipped hairy hairs on its leaves. The flower cluster bears clusters of flower heads lined with shiny, oily, yellow-green phyllaries with transparent tips. The fruit is a tiny achene up to a millimeter long. The plant reproduces from seed except in very rare occasions when it reproduces vegetatively by layering.

Artemisia palmeri is a rare species of sagebrush known by the common names San Diego sagewort and Palmer sagewort. It is native to northern Baja California and San Diego County, California, where its natural habitat is sandy coastal ravines and river drainages. Most of this habitat has been destroyed as the land has been claimed for human use. It is occasionally found farther inland in chaparral plant communities in the region. This is a perennial or biennial herb producing brittle erect or spreading stems 1 to 3 meters tall. The base is woody. The aromatic foliage is made up of long, narrow leaves deeply cut into several narrow, pointed lobes. The flower cluster contains clusters of flower heads containing pale yellow hairy disc florets. The fruit is a tiny achene about a millimeter long. It is rumored David Bowie ate this type of sagewort while writing his album Low. This plant does best in part shade, but can handle full sun or full shade as well. It is an attractive looking plant and would make a great addition to any garden, not to mention its habitat value, which is an added bonus.

Artemisia pycnocephala is a species of sagebrush in the Asteraceae (Sunflower) family known by the common names Beach Sagewort, Beach Wormwood and Coastal Sagewort. This plant is native to the western United States coastline extending from Oregon to Central California. It is a leafy perennial wormwood forming clumps about half a meter in height. It extends erect stems covered in dense foliage which ranges in color from light green to nearly white. The fuzzy flower clusters are studded with small lobular leaves and rounded yellowish flower buds. The plant is aromatic but much less so than are other wormwoods. It is restricted to the immediate coast, often in dunes, where it is protected from temperature extremes. There is a popular cultivar known as 'David's Choice'.

David’s choice sagebrush (Artemisia pycnocephala 'David’s Choice') is a compact, silvery shrub with soft, velvety foliage. It was selected from native sagebrush at Point Reyes, north of San Francisco, and introduced by David Amme in 1980.

This drought-adapted plant thrives in well-drained, sandy soils and prefers coastal conditions, though it can handle partial shade inland. While its yellow flowers are inconspicuous, they can be trimmed back to maintain its neat, rounded form.

David’s choice sagebrush is an excellent choice for borders or as a groundcover, providing a striking contrast to darker green plants like Ceanothus or low-growing Iris. It also offers forage for wildlife, contributing to a healthy garden ecosystem.

Artemisia rothrockii is a North American species of sagebrush known by the common names timberline sagebrush and Rothrock's sagebrush. Artemisia rothrockii is endemic to California, where it is native to parts of the Sierra Nevada, the White Mountains, and the San Bernardino Mountains. It has been recorded from the Kern Plateau, Mount Dana, Angora Peak, and the vicinity of Fallen Leaf Lake. It grows in the dry transition between mountain meadows and forests. It can also tolerate wet conditions, surviving waterlogging during snowmelt.

Artemisia spiciformis is a North American species in the sunflower family, with the common name Snowfield sagebrush. It grows at high elevations in the mountains, frequently in the vicinity of late-season snow. It is found in the Western United States in California, Oregon, Washington, Idaho, Nevada, Utah, Wyoming, and Colorado. Artemisia serrata is an aromatic shrub up to 80 cm (32 inches) tall. It has several stems and many small flower heads. It can be round on rocky slopes, open meadows, etc.

Artemisia spinescens is a North American species of sagebrush in the sunflower family, known by the common name budsage. Many sources treat the species separately from genus Artemisia and named Picrothamnus desertorum. This separation has not, however, been supported by genetic analysis. Artemisia spinescens is native to the western United States from southern + eastern California and the Great Basin, north to Idaho and Montana, and east to western Colorado and northwestern New Mexico. Artemisia spinescens grows in scrub and other habitat on clay and gravel-rich soils. It thrives on salty soils, growing with other salt-tolerant plants such as saltbushes ('Atriplex sp. ). It is adapted to very dry climates. Artemisia spinescens is a squat shrub forming a rounded bush up to 30 to 50 centimeters in maximum height. Its tangled branches are woolly when new and thorny and rough when aged. The stem is woody and corky. The strongly aromatic foliage is made up of many small, fuzzy leaves divided into narrow, pointed segments. It is deciduous, dropping its leaves during the dry summer when it becomes dormant. The inflorescence is a raceme of small clusters of flower heads sprouting from leaf axils. Each head contains several tiny bell-shaped sterile disc florets and a few fertile ray florets. The fruit is a tiny hairy achene less than a millimeter long. Uses. This plant is considered good forage for wild and domestic grazing animals early in the season when the foliage is new and soft. Later in the season when the plant produces large quantities of bitter volatile oils it becomes unpalatable.

Artemisia suksdorfii is a species of sagebrush known by the common names coastal mugwort, coastal wormwood, and Suksdorf sagewort. It is native to coastal western North America from British Columbia to northern California, and it is also known from the Channel Islands of California. It grows in coastal drainages and other habitat near the ocean. This is a rhizomatous perennial herb producing many erect stems one half to two meters in height. The unbranched stems are brownish and have woody bases. The leaves are narrow and lobed, green and hairless on top and white and woolly underneath. The flower cluster is generally spike-like, up to 30 centimeters long and a few wide. It contains many clusters of small flower heads with shiny yellow-green phyllaries and yellow disc and pistillate florets. The fruit is a tiny achene less than a millimeter long.

Big Sagebrush (Artemisia tridentata) is a dense, silvery-gray shrub with an upright form, growing up to 4 feet tall and wide. Its highly aromatic foliage lasts year-round, and, unlike other sages, it develops a true woody trunk and branches, making it long-lived. In maturity, the twisted trunk adds unique visual appeal. The flowers, small and yellow-green, are often inconspicuous.

This plant thrives in full sun and well-drained soil, is nitrogen-fixing, and is drought-tolerant. It provides significant wildlife value, attracting a variety of insects, birds, and small mammals with its flowers and seeds.Big Sagebrush (Artemisia tridentata) is a dense, silvery-gray shrub with an upright form, growing up to 4 feet tall and wide. Its highly aromatic foliage lasts year-round, and, unlike other sages, it develops a true woody trunk and branches, making it long-lived. In maturity, the twisted trunk adds unique visual appeal. The flowers, small and yellow-green, are often inconspicuous.

This plant thrives in full sun and well-drained soil, is nitrogen-fixing, and is drought-adapted. It provides significant wildlife value, attracting a variety of insects, birds, and small mammals with its flowers and seeds.

Basin Big Sagebrush is a common native shrub that grows in northern, southern and central California. It is slow growing and moderately long-lived. It grows in a rounded form to a height of 9 feet, with active growth during the spring and summer. Flowers are green and striking, and bloom in the late summer. Leaves are gray-green, and remain on the plant throughout the year. It tends to grow in dry valleys and slopes, at elevations from 2600-6200 feet.

Mountain Sagebrush (Artemisia tridentata ssp. vaseyana) is a common native shrub that grows in northern, southern and central California. It is slow growing and long-lived. It grows in an upright form to a height of 7 feet, with active growth during the spring, summer, fall. Leaves are gray-green and deciduous. It tends to grow in dry valleys and slopes, at elevations from 5900-9800 feet.

Wyoming Sagebrush is a common native shrub that grows in Central and Northern California, primarily in the Warner Mountains and Modoc Plateau regions. It is slow growing and long-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 bloom in the late summer Leaves are gray-green and deciduous. It tends to grow in dry valleys and slopes, at elevations from 0-7200 feet.

Asclepias albicans is a species of milkweed known by the common names whitestem milkweed and wax milkweed. It is native to the Mojave and Sonoran Deserts of California, Arizona, and Baja California. This is a spindly erect shrub growing usually 1 to 3 meters tall, but known to approach four meters. The sticklike branches are mostly naked, the younger ones coated in a waxy residue and a thin layer of woolly hairs. Leaves are ephemeral, growing in whorls of three on the lower branches and falling off after a short time. They are linear in shape and up to 3 centimeters long. The flower cluster is an umbel appearing at the tips of the long branches and sprouting from the sides at nodes. The flower cluster contains many small purple-tinted greenish flowers, each with a central array of bulbous hoods, and corollas reflexed back against the stalk. The plant may flower in any season except summer. The fruit is a large, long, thick follicle which dangles in bunches from the branch nodes.

Asclepias asperula is a species of milkweed native to the southwestern United States and northern Mexico. Its common names include antelope horns, green-flowered milkweed, and spider antelope horns. It is a perennial plant growing to 0.6-2 meter (1-2 feet) tall, with clustered greenish-yellow flowers with maroon highlights. It blooms from April through June, and favors moist, sandy or rocky soil. Like several other species of milkweed, A. asperula is a food for monarch butterfly caterpillars. Along with being a source of nutrition for monarchs, the plants also contain alkaloids that the monarchs retain, making them unpalatable and poisonous to predators. For the same reason, A. asperula can be poisonous to livestock and other animals, including humans.

California Milkweed (Asclepias californica) is a species in the Apocynaceae (Dogbane) family. It is native to California and northern Baja California from the East Bay region southward and the foothills of the Sierra.

This flowering perennial has thick, white, woolly stems that bend or run along the ground. The plentiful, hanging flowers are rounded structures.

The flowers are dull to bright shades of lavender or pink and form an attractive contrast with the grey-to-white foliage. This plant was eaten as candy by the Kawaiisu tribes of Indigenous California; the milky sap within the leaves is said to be flavorful and chewy when cooked.

To maximize Monarch butterflies reaching their overwintering areas, plant only locally native milkweed species.

Asclepias cordifolia is a species of milkweed commonly called Heart-leaf milkweed or Purple milkweed (not to be confused with Asclepias purpurascens, also commonly called Purple milkweed). It is native to the western United States (California, Nevada, Oregon), growing between 50-2000 meter elevation in the northern Sierra and Cascade ranges. Heart-leaf milkweed was valued by the Native American Miwok for its stems, which they dried and processed into cordage (string and rope). Monarch butterfly caterpillars eat the Heart-leaf milkweed leaves, which contain alkaloids that cause the butterfly to be unpalatable to predators. The species name, cordifolia (Latin for 'heart-leaved'), refers to the heart-shaped leaves, while the genus name honors the Greek physician Asclepius. Heart-leaf milkweed is a perennial that grows to a height of 0.3-0.6 meter, with dark red-purple flowers whose hoods are slightly elevated above the base of the corolla. The flower structure is unusual-it has five stamens fused into a column, with five circular attachments called 'hoods', and an anther head surrounding the large stigma at the flower's center. The fruit (photo at left) is a follicle with many flat seeds that have silky hairs which disperse easily in the wind. The large opposite leaves are heart-shaped, or heart-shaped. The plant grows in open or shaded woodland, often on rocky slopes and in mixed coniferous forest.

Asclepias cryptoceras is a species of milkweed known by the common names pallid milkweed and Humboldt Mountains milkweed. It is native to the western United States, where it grows in many types of habitat, especially dry areas. This is a perennial herb growing low against the ground or drooping. It arises from a fleshy, woody rhizome-like root. The thick leaves are round to heart-shaped and arranged oppositely on the short stem. The flower cluster is a cluster of small flowers with centers of bright to dull pink hoods surrounded by pale-colored reflexed corollas. The fruit is a follicle held erect on a small stalk.

Asclepias eriocarpa is native to California and adjacent parts of Nevada and Baja California, where it grows in many habitat types, especially dry areas. In California it is found primarily in the Coast Ranges from Mendocino County southward into Mexico, in the Sierra foothills, and in the northern part of the Central Valley. It is an erect perennial herb which is usually coated in a thick layer of white hairs. The leaves are lance-shaped to oval, rippled, and arranged oppositely in pairs or in whorls of 3 or 4. The flower cluster is a large umbel-like cluster of flowers. Each flower is white to cream and usually tinted with bright pink. It has a central array of rounded hoods and a corolla reflexed against the stalk. The fruit is a large, woolly follicle. The plant is used as a source of fiber and medicine by several California Indian groups, including the Ohlone and Luiseno. In the garden it makes a striking specimen, especially when massed. All milkweeds are important to monarch butterflies.

Asclepias erosa is a species of milkweed known commonly as desert milkweed. It is native to southern California, Arizona, and northern Baja California, where it is most abundant in the desert regions. This milkweed is a perennial herb with erect yellow-green stems and foliage in shades of pale whitish-green to dark green with white veining. It may be hairless to very fuzzy. The sturdy, pointed leaves grow opposite on the stout stem. Atop the stem is a rounded umbel of yellowish or cream-colored flowers. Each flower has thick, reflexed corollas beneath a flower center composed of rounded, horned filaments. The plant is filled with a viscous sap that was roasted to a solid and enjoyed as a sort of chewing gum by local Native American groups.

Narrowleaf Milkweed (Asclepias fascicularis) is a flowering perennial best known for the Monarch butterflies it will attract into the garden. Its long, thin pointed leaves give the plant a soft, wispy look. It blooms in summer to fall, with clusters of lavender or pinkish white flowers, each one an interesting button shape. The fruits are smooth pods, which split open to spill seeds along with plentiful silky hairs that may carry the seeds through the air.

This plant grows fast to 3 feet tall and is dormant in winter, often dying back to the ground. It will take full sun but is adaptable to most conditions, being easy to grow in soils with good drainage, even with no summer water. It can self-seed if the seed pods are not removed

This species is probably the single most important host plant for Monarch Butterflies in California, attracting them and hosting their caterpillars. It is crucial to not use any pesticide on or around the plant, because doing so will be fatal to the caterpillars. The plant also provides resources for many beneficial creatures, including native bees. Don't cut the dry stems down too soon as Orioles may use them for nesting.

Asclepias nyctaginifolia is a species of milkweed known by the common name Mojave milkweed. It is native to the southwestern United States from California to New Mexico, where it grows mainly in desert habitat. This is a perennial herb growing up to about half a meter in maximum height when erect, but often bending or drooping. The thick leaves are oval to lance-shaped and arranged in opposite pairs about the stem. The leaves and stem are generally slightly hairy. The flower cluster is a dense umbel up to 8 centimeters wide and packed with pink-tinted pale green flowers. The fruit is a large follicle up to 9 centimeters long.

Asclepias solanoana is a rare species of milkweed known by the common names serpentine milkweed, prostrate milkweed, and solanoa. It is endemic to California, where it grows only in the North Coast Ranges north of the San Francisco Bay Area. This is a robust perennial herb producing smooth purple stems which lie prostrate along the ground. The thick leaves are arranged oppositely in pairs along the stem. The leaf has an oval or heart-shaped blade supported on a short petiole. The inflorescence is a heavy spherical cluster of flowers. Each flower has a central array of rounded hoods which are pink to brown and a corolla which is reflexed against the stalk or extends outwards.

Named for its abundant clusters of starlike flowers, showy milkweed (Asclepias speciosa) is an eye-catching native plant selection for the butterfly garden. In the summer months, showy milkweed is covered in fragrant blooms in delicate shades of pink, white, and purple. The large leaves are an attractive grayish-green color.

After blooming, the plant produces large pods that contain seeds with long silky tassels, so they can be dispersed by the wind. Individual plants spread by underground rhizomes into an expanding clump. Showy milkweed has thick, sturdy stems and an upright growth habit. It can reach up to 6 ft in height. The plant goes dormant during the winter months. 

Showy milkweed is an important butterfly host plant, especially for the Monarch butterfly. Adult butterflies feed on the flower nectar and caterpillars eat the leaves. The blooms also attract hummingbirds. Like other milkweeds, this plant produces alkaloids that, when consumed, protect the caterpillars from predators.

Showy milkweed is easy to care for. It grows well in full sun and should be planted in dry, well-drained soil. Remove seed pods to prevent self-sowing. Large clumps can be pruned during the winter dormancy season.

Grows best in loamy, medium draining soil. Selection from Davis, CA.

Asclepias subulata is a species of milkweed known commonly as the rush milkweed or ajamete. This is an erect perennial herb which loses its leaves early in the season and stands as a cluster of naked stalks. Atop the stems are flower clusters of distinctive flowers. Each cream-white flower has a reflexed corolla that reveals the inner parts, a network of five shiny columns, each topped with a tiny hook. The fruit is a pouchlike follicle that contains many flat, oval seeds with long, silky hairlike plumes. This milkweed is native to the desert southwest of the United States and northern Mexico.

Asclepias vestita is a species of milkweed known by the common name woolly milkweed. It is endemic to California, where it grows in many habitats across the state, from mountains to desert to valley. This is a robust perennial herb growing mostly upright or slightly bending. The thick leaves are oval to narrowly lance-shaped. The stem and leaves often have a coat of light-colored hairs, sometimes thick and woolly. The inflorescence is an umbel-shaped array to a spherical cluster of yellowish flowers. The flowers may be tinted with brown or purple. The fruit is a large yellowish follicle containing many silky-haired seeds.

Astragalus acutirostris is a species of milkvetch known by the common name sharpkeel milkvetch. It is native to the Mojave Desert and surroundings of California, Nevada, and Arizona, where it grows in dry, sandy, gravelly areas. Astragalus acutirostris is an annual legume growing a hairy reddish stem no more than 30 centimeters long along the ground or slightly upright. The small leaves are made up of several pairs of small oblong leaflets, each less than a centimeter long and often with notched tips. The inflorescence contains one to six white or pinkish-tinted pealike flowers, each with a banner that curves back. Astragalus acutirostris is an annual legume growing a hairy reddish stem no more than 30 centimeters long along the ground or slightly upright. The small leaves are made up of several pairs of small oblong leaflets, each less than a centimeter long and often with notched tips. The inflorescence contains one to six white or pinkish-tinted pealike flowers, each with a banner that curves back. The fruit is a slightly curved, narrow legume pod 1 to 3 centimeters long. The pod is thin-walled and coated sparsely in white hairs like the rest of the plant.

Astragalus agnicidus is a rare species of milkvetch known by the common name Humboldt County milkvetch. It is endemic to northern California, where it is known only from two populations in Humboldt County and one in Mendocino County. The plant was undescribed until the 1950s. Until then it was known only from one 8-acre (32,000 m2) ranch in Humboldt County, where sheep ranchers blamed the unnamed species for the deaths of their animals, which may have eaten it. They eradicated the plant from their land, and by the time it was formally described and named in 1957 it was thought to be extinct. The species name given the plant, agnicidus, means "lamb-killer".

Astragalus agrestis is a species of milkvetch known by the common names purple milkvetch, purple loco, and field milkvetch. It is native to much of western and northern North America from most of Canada to the southwestern United States, as well as eastern Asia. It grows in vernally moist areas such as meadows, and is often found in sagebrush. This is a perennial herb growing a slender but sturdy stem from an underground caudex. It leans or grows upright to a maximum height near 30 centimeters. The stem is often roughly hairy. Alternately arranged leaves are up to 10 centimeters long and made up of several pairs of leaflets up to 2 centimeters long each. They are oval to lance-shaped and may have notched tips. The inflorescence is an oval-shaped cluster of up to 15 purple or pink-tinted to nearly white pealike flowers. Each flower is up to 2 centimeters long. This is a perennial herb growing a slender but sturdy stem from an underground caudex. It leans or grows upright to a maximum height near 30 centimeters. The stem is often roughly hairy. Alternately arranged leaves are up to 10 centimeters long and made up of several pairs of leaflets up to 2 centimeters long each. They are oval to lance-shaped and may have notched tips. The inflorescence is an oval-shaped cluster of up to 15 purple or pink-tinted to nearly white pealike flowers. Each flower is up to 2 centimeters long. The fruit is an oval-shaped legume pod up to a centimeter long. It is dark colored with white hairs and dries to a papery texture.

Astragalus albens is a species of milkvetch known by the common names Cushenbury milkvetch and silvery-white milkvetch. It is endemic to San Bernardino County, California, where it is known from the northern slopes of the San Bernardino Mountains near the settlement of Cushenbury. Most of the plants are located in the woodland and scrub of the slopes between Big Bear in the mountains and Lucerne Valley in the Mojave Desert at the foot of the range. It grows in habitat rich in carbonate rock. It is a federally listed endangered species which is known from 30 to 50 populations. There are a total of about 7000 plants, fewer in drought years. Astragalus albens is an annual or perennial herb producing a prostrate mat of delicate stems coated densely in silvery hairs. The leaves are generally a few centimeters long and made up of several gray-green oval-shaped leaflets less than a centimeter long each. The inflorescence arises upright from the low patch of foliage and bears up to 14 pealike flowers. Each flower is dark-veined light to deep purple with a spot of white or light pink in the throat. The fruit is a legume pod between one and two centimeters long. It is roughly hairy and crescent-shaped, drying to a thick papery texture. The main threat to this species is limestone mining, a large industry in this part of the San Bernardino Mountains. This form of mining alters the local habitat by physically removing plant life for quarries, road construction, and load dumping. It also produces major changes in the hydrology of the area and releases large amounts of carbonate dust into the air which combines with water and forms a very thin layer of what is essentially cement over the habitat. Most of the populations of this plant are located on sites of active mining or sites which are targeted for mining in the future. Most of these sites are part of San Bernardino National Forest, and there are plans to set aside pieces of habitat for this and other endemics. Other threats to the species include off-road vehicle use and urban development.

Astragalus andersonii is a species of milkvetch known by the common name Anderson's milkvetch. It is native to eastern California and western Nevada, where it is found in the plateaus at the foot of the Sierra Nevada, including the Modoc Plateau. This is a small perennial herb forming a thick patch on the ground, the stems reaching about 20 centimeters in maximum length. The plant is coated in dense gray to white wavy hairs. The leaves are up to 10 centimeters long and made up of several oval-shaped leaflets. The inflorescence is a projecting or upright array of 12 to 26 pealike flowers. Each flower is white, often purple-tinted or purple-veined, and between 1 and 2 centimeters long. The fruit is a curved legume pod 1 to 2 centimeters long. This is a small perennial herb forming a thick patch on the ground, the stems reaching about 20 centimeters in maximum length. The plant is coated in dense gray to white wavy hairs. The leaves are up to 10 centimeters long and made up of several oval-shaped leaflets. The inflorescence is a projecting or upright array of 12 to 26 pealike flowers. Each flower is white, often purple-tinted or purple-veined, and between 1 and 2 centimeters long. The fruit is a curved legume pod 1 to 2 centimeters long. It is coated in very long white hairs and dries to a thick papery texture, the beans inside rattling with the wind.

Astragalus anxius is a rare species of milkvetch known by the common names troubled milkvetch and Ash Valley milkvetch. It is endemic to northern Lassen County, California, where it grows in the volcanic soil of the Modoc Plateau. It was formally described in 1992. There are only 6 known occurrences, some of which are threatened by livestock trampling. Astragalus anxius is a perennial herb forming a matted patch of slender, delicate stems no longer than 20 centimeters. It is coated thinly in wavy hairs. The leaves are a few centimeters long and made up of several leaflets. The inflorescence contains 7 to 15 pealike flowers. Each flower is bicolored, the lower petals usually white and the upper banner petals purple to purple-veined white. The fruit is a hairy, oval-shaped legume pod up to half a centimeter long which dries to a papery texture. Astragalus anxius is a perennial herb forming a matted patch of slender, delicate stems no longer than 20 centimeters. It is coated thinly in wavy hairs. The leaves are a few centimeters long and made up of several leaflets. The inflorescence contains 7 to 15 pealike flowers. Each flower is bicolored, the lower petals usually white and the upper banner petals purple to purple-veined white. The fruit is a hairy, oval-shaped legume pod up to half a centimeter long which dries to a papery texture.

Astragalus asymmetricus is a species of milkvetch known by the common name San Joaquin milkvetch. It is endemic to California, where it grows in grassy and disturbed areas in the Central Valley and nearby parts of the Central Coast Ranges and San Francisco Bay Area. This is a sturdy perennial herb growing a thick, erect stem to heights between 50 and 120 centimeters. It is coated in long hairs. The leaves are up to 20 centimeters long and are made up of many pairs of leaflike leaflets, each up to 2.5 centimeters long and varying in shape from linear to oval. The flower cluster contains 15 to 45 cream-colored pealike flowers 1 to 2 centimeters long. The fruit is a slightly inflated hairy legume pod up to 4 centimeters long which hangs in bunches from the dried flower cluster.

Astragalus austiniae is a species of milkvetch known by the common name Austin's milkvetch. It is native to the Sierra Nevada of California and Nevada in the vicinity of Lake Tahoe. It is a plant of the alpine climate of the high mountains, where it tolerates exposed areas. Astragalus austiniae is a dwarfed perennial herb forming small clumps in the rock litter no taller than about 11 centimeters. Stems and foliage are coated densely in cottony, silvery hairs. The leaves are up to 5 centimeters long and are made up of several keeled oval-shaped leaflets. The inflorescence is a woolly headlike cluster of 4 to 14 pink or purple-tinted white pealike flowers each around a centimeter long. Astragalus austiniae is a dwarfed perennial herb forming small clumps in the rock litter no taller than about 11 centimeters. Stems and foliage are coated densely in cottony, silvery hairs. The leaves are up to 5 centimeters long and are made up of several keeled oval-shaped leaflets. The inflorescence is a woolly headlike cluster of 4 to 14 pink or purple-tinted white pealike flowers each around a centimeter long. The fruit is a woolly legume pod less than a centimeter long.

Astragalus bernardinus, known by the common name San Bernardino milkvetch, is a species of milkvetch. It is a plant of desert and dry mountain slope habitat. The plant is native to the San Bernardino Mountains of Southern California. It is also found in the Mojave Desert sky islands, in the Ivanpah Mountains and nearby New York Mountains which straddle the California-Nevada state line. The plant is native to the San Bernardino Mountains of Southern California. It is also found in the Mojave Desert sky islands, in the Ivanpah Mountains and nearby New York Mountains which straddle the California-Nevada state line. Astragalus bernardinus is a slender, wiry perennial herb growing in twisted clumps, sometimes clinging to other plants for support. The stems are 10 to 50 centimeters long and mostly naked, coated partly in stiff hairs. The leaves are up to 14 centimeters long and are made up of widely spaced pairs of lance-shaped leaflets. The inflorescence is a loose cluster of up to 25 light purple pealike flowers. The fruit is a pale-colored legume pod up to 3 centimeters long which dries to a papery texture.

Astragalus bicristatus is a species of milkvetch known by the common names crested milkvetch and two-crested milkvetch. It is endemic to southern California, where it grows in the coniferous forests of the San Gabriel and San Bernardino Mountains of the Transverse Ranges. Astragalus bicristatus is a perennial herb sprawling outwards with stems to a maximum length approaching half a meter. The leaves are up to 14 centimeters long and are made up of very widely spaced narrow linear leaflets. The stems and foliage have sparse grayish hairs, giving them a rough texture. The inflorescence is a loose array of up to 20 pealike flowers. Each flower is between 1 and 2 centimeters long and is purple-tinted white to light greenish yellow. Astragalus bicristatus is a perennial herb sprawling outwards with stems to a maximum length approaching half a meter. The leaves are up to 14 centimeters long and are made up of very widely spaced narrow linear leaflets. The stems and foliage have sparse grayish hairs, giving them a rough texture. The inflorescence is a loose array of up to 20 pealike flowers. Each flower is between 1 and 2 centimeters long and is purple-tinted white to light greenish yellow. The fruit is a hanging capsule 2 to 4 centimeters long and curved or crescent-shaped. It is fleshy when immature and leathery to woody when dried.

Astragalus bolanderi is a species of milkvetch known by the common name Bolander's milkvetch. It is native to western Nevada and parts of the Sierra Nevada in California. It grows in dry, rocky habitat on mountain and plateau. Astragalus bolanderi is a perennial herb producing erect, drooping, or creeping stems up to 40 centimeters long. The stems are mostly naked, with a sparse coat of long, wavy hairs and a few leaves on the upper parts. The leaves are up to 16 centimeters long and are made up of very widely spaced oval to nearly lance-shaped leaflets each up to 2 centimeters long. The leaflet has a hard midrib that ends in a point at the tip. Astragalus bolanderi is a perennial herb producing erect, drooping, or creeping stems up to 40 centimeters long. The stems are mostly naked, with a sparse coat of long, wavy hairs and a few leaves on the upper parts. The leaves are up to 16 centimeters long and are made up of very widely spaced oval to nearly lance-shaped leaflets each up to 2 centimeters long. The leaflet has a hard midrib that ends in a point at the tip. The inflorescence is a dense cluster of 7 to 18 pealike flowers. Each flower is between 1 and 2 centimeters long and is purple-tinted white. The fruit is an inflated, curved legume pod up to 3 centimeters long. It dries to a thick papery texture.