Eriodictyon altissimum is a rare species of flowering plant in the borage family known by the common name Indian Knob mountainbalm. It is endemic to San Luis Obispo County, California, where it is known from only about six occurrences in the Irish Hills on the coast and nearby Indian Knob.
Arctostaphylos tomentosa is a species of manzanita known by the common name woollyleaf manzanita or woolley manzanita. This shrub is endemic to California.
Ceanothus impressus is a species of shrub in the family Rhamnaceae known by the common name Santa Barbara ceanothus. It is endemic to the Central Coast of California, where it is known from San Luis Obispo and Santa Barbara Counties. It occurs in chaparral habitat.
Hooveria purpurea is a species of flowering plant related to the agaves known by the common name purple amole. This species of soap plant is endemic to California, where it grows in the Santa Lucia Range, in the Central Coast region. There are two varieties of this plant, and both are believed to be quite rare. It is a federally listed threatened species.
Erigeron blochmaniae is a species of flowering plant in the family Asteraceae known by the common names Blochman's erigeron and Blochman's leafy daisy.
Isocoma menziesii is a species of flowering plant in the family Asteraceae, known by the common name Menzies' goldenbush.
Arctostaphylos luciana is a species of manzanita known by the common name Santa Lucia manzanita, is endemic to California.
Arctostaphylos obispoensis is a species of manzanita, known by the common names bishop manzanita and serpentine manzanita, endemic to California.
Calycadenia villosa is an uncommon species of flowering plant in the family Asteraceae known by the common name dwarf western rosinweed. It is endemic to central California, where it is known from a limited distribution in the Central Coast Ranges in Monterey County and San Luis Obispo County, with a few populations in Santa Barbara and western Fresno Counties. There are perhaps 16 occurrences.
Cirsium loncholepis is a rare species of thistle known by the common name La Graciosa thistle. It is endemic to California, where it is known from about 15 remaining occurrences in wetlands where southwestern San Luis Obispo County borders northwestern Santa Barbara County. It grows in coastal scrub and sand dunes, marshes, and moist grasslands in the watersheds of local rivers, including the Santa Maria River. It is a federally listed endangered species.
Cirsium rhothophilum is a rare North American species of thistle known by the common name surf thistle. It is endemic to California, where it is known only from the coastline around the border between San Luis Obispo and Santa Barbara Counties. It grows in sand dunes and coastal scrub near the beach.
Erigeron sanctarum is an uncommon species of flowering plant in the family Asteraceae known by the common names saints fleabane and saints daisy. It is endemic to California, where it is known from San Luis Obispo and Santa Barbara Counties including two of the Channel Islands.
Hosackia incana, synonym Lotus incanus, is a species of legume native to California. It is known by the common name woolly bird's-foot trefoil. It is endemic to the Sierra Nevada of California, where it grows in forests and other mountain habitat.
Acmispon prostratus, synonyms Lotus nuttallianus and Syrmatium prostratum, is a species of legume native to California and northwestern Mexico. It is known by the common names beach lotus, Nuttall's lotus, and wire bird's-foot trefoil. It is native to Baja California and just into San Diego County, California, where it is a resident of coastal habitats, such as beaches and bluffs.
Malacothrix squalida is a rare species of flowering plant in the family Asteraceae known by the common name Santa Cruz desertdandelion. It is endemic to Santa Cruz and Anacapa Islands, two of the eight Channel Islands of California, where it grows on rocky seaside bluffs and cliffs. The plant is very limited in distribution and today exists only in degraded habitat on these two small islands. It was last collected from Santa Cruz Island in 1968, and two populations were noted on Anacapa Island in 1998; in drought years there may be no plants at all. It became a federally listed endangered species in 1997. This is an annual herb growing a hairless, waxy stem 20 to 30 centimeters in maximum height. The leaves are sharply lobed. The inflorescence is an array of flower heads lined with oval-shaped phyllaries. The ray florets are 1 to 2 centimeters and light yellow in color.
Monardella undulata is an uncommon species of flowering plant in the mint family known by the common name curlyleaf monardella. It is an annual herb and is endemic to the coast of California.
Senecio blochmaniae is an uncommon species of flowering plant in the aster family known by the common names dune ragwort and Blochman's ragwort. It is endemic to the Central Coast of California, where it is known only from the direct coastline of San Luis Obispo and Santa Barbara Counties. It grows in sand dunes and sandy areas on coastal floodplains. It is a subshrub producing several arching stems often well exceeding a meter tall from a thick taproot. The stems are covered in many leaves, which are linear in shape, thick, and measure up to 12 centimeters long. The lower leaves become dry and curl up. The flower heads are lined by about 13 green-tipped phyllaries. They contain many yellow disc florets and each has usually 8 narrow yellow ray florets about a centimeter long.
Suaeda californica is a rare species of flowering plant in the amaranth family known by the common name California seablite. It is now endemic to San Luis Obispo County, California, where it is known from a few occurrences in the marshes around Morro Bay, historical populations around San Francisco Bay have been extirpated.
Malacothrix junakii is a rare species of flowering plant in the family Asteraceae known by the common names Anacapa Island desert-dandelion, Junak's desertdandelion, and Junak's malacothrix. It is endemic to Anacapa Island, one of the Channel Islands of California, where it is known from just two occurrences. It occurs in the coastal scrub of the island. It was described to science as a new species in 1997.
Mucronea californica is a rare species of annual plant in the family Polygonaceae known by the common names California spineflower or California mucronea. An ephemeral plant found growing in the sandy microhabitats of coastal sage scrub, chaparral and dunes, this plant is threatened by the urbanization and development of its viable habitat and has been locally extirpated over much of its range. It has small, white to pink flowers that top inflorescences spined with awns.
