Malacothamnus (bushmallow) is a genus of shrubs found throughout much of mainland California and on three of the Channel Islands. Outside of California, Malacothamnus is known from the northern half of Baja California and from a few disjunct locations in Arizona. Plants of this genus are most commonly found in early-successional, post-burn plant communities. Malacothamnus are currently thought to be most closely related to the Iliamnas of the US interior and the Phymosias of Mexico, Central America, and the Caribbean.
Arctostaphylos pilosula is a species of manzanita, known by the common names La Panza manzanita and Santa Margarita manzanita, that is endemic to California.
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.
Ceanothus masonii is a species of shrub in the buckthorn family, Rhamnaceae, known by the common name Mason's ceanothus. It is endemic to Marin County, California, where it is known only from an area near Bolinas on the Point Reyes National Seashore. It grows in the coastal chaparral on the windblown bluffs..
Constancea is a monotypic genus of flowering plants in the family Asteraceae containing the single species Constancea nevinii, which is known by the common name Nevin's woolly sunflower. It is endemic to three of the Channel Islands of California, where it grows in coastal scrub habitat. This is a small shrub or subshrub generally growing up to one or 1.5 meters tall, and taller when an erect form, with a branching, woolly stem. The whitish, woolly oval leaves may be up to 20 centimeters long and are divided into many narrow lobes with edges curled under. The inflorescence is a cluster of 10 to 50 or more small flower heads, each on a short peduncle. The flower head has a center of hairy, glandular, star-shaped yellow disc florets and a fringe of four to nine yellow ray florets, each about 2 millimeters long. The fruit is an achene a few millimeters long with a small pappus at the tip.
Hosackia pinnata, synonym Lotus pinnatus, is a species of legume native to western North America from British Columbia to California. It is known by the common names meadow bird's-foot trefoil and bog bird's-foot trefoil. Its distribution extends into British Columbia in just a few rare occurrences near Nanaimo. It grows in moist to wet habitat, such as bogs and spring meadows. It is a hairless perennial herb lined with leaves each made up of green oval leaflets each 1 to 2.5 centimeters in length. The inflorescence is an array of up to 10 pealike flowers between 1 and 2 centimeters long. Each flower has a bright yellow banner, or upper petal, and white lower petals. The fruit is a slender, elongated legume pod up to 5 centimeters long but just a few millimeters wide.
Malacothamnus clementinus is a rare species of flowering plant in the mallow family known by the common name San Clemente Island bushmallow. It is endemic to San Clemente Island, one of the Channel Islands of California, where it is known from fewer than ten occurrences in the steep, rocky seaside canyons.
Malacothamnus davidsonii is a species of flowering plant in the mallow family known by the common names Tujunga bushmallow and Davidson's bushmallow. It is endemic to Los Angeles County, California, where it primary occurs in and near Big Tujunga Canyon, Little Tujunga Canyon, and Tujunga Wash. The common name Tujunga bushmallow alludes to its geographic distribution. Plants of what has historically been considered Malacothamnus davidsonii from Monterey and San Luis Obispo counties in California were described as the new species Malacothamnus discombobulatus in 2023 based on phylogenetic, morphological, and geographic evidence.
Malacothamnus densiflorus is a species of flowering plant in the mallow family, which has two varieties. It is endemic to the Peninsular Ranges of southwestern California and northwestern Baja California.
Malacothamnus fasciculatus is a species of flowering plant in the mallow family, which has four varieties. It is endemic to southwestern California and northwestern Baja California.
Monardella beneolens is a rare species of flowering plant in the mint family known by the common name sweet-smelling monardella.
Nitrophila mohavensis is a rare species of flowering plant in the family Amaranthaceae known by the common name Amargosa niterwort. It is endemic to Nye County in southwestern Nevada and Inyo County, in eastern California.
Pyrrocoma uniflora is a species of flowering plant in the family Asteraceae known by the common name plantain goldenweed. It is native to western North America from central Canada to California to Colorado, where it grows in several types of habitat, including forest and meadows with alkali soils, such as those near hot springs. It is a perennial herb growing up to 40 centimeters tall, the stems reddish and usually with a thin to thick coating of woolly fibers. The lance-shaped, toothed leaves are usually woolly, the largest near the base of the plant reaching up to 12 centimeters in length. The inflorescence is a single flower head or a cluster of a few heads, each lined with woolly phyllaries. The head contains yellow disc and ray florets. The fruit is an achene which may be over a centimeter long including its long pappus.
Packera ganderi is a rare species of flowering plant in the aster family known by the common name Gander's ragwort. It is endemic to southern California, where it is known from a few occurrences in San Diego and Riverside Counties.
Verbesina dissita is a rare species of flowering plant in the family Asteraceae known by the common name bigleaf crownbeard. It is native to northern Baja California in Mexico, where it is known from about 23 occurrences, although some of these may have been extirpated or are vulnerable to destruction. It is also known from a 3.2-kilometer section of the coastline near Laguna Beach in southern California, where it is susceptible to extirpation in a highly developed section of valuable oceanfront land. Other threats include erosion and competitive introduced species of plants. This is a federally listed threatened species of the United States.
Eriogonum spectabile is a rare species of wild buckwheat known by the common name Barron's buckwheat. It is endemic to Plumas County, California, where it is known from two occurrences in Lassen National Forest near Chester. There are approximately 250 individuals in existence. It grows in scrubby, forested mountain habitat, only on glaciated andesite substrates. This rare plant was discovered in 1997 and described to science as a new species in 2001.
Heterotheca monarchensis is a rare species of flowering plant in the family Asteraceae known by the common names monarch goldenaster and sequoia false goldenaster. It is endemic to Fresno County, California, where it is known from only one location near Boyden Cave in the Kings River Canyon. It grows in the limestone cliffs of this Sierra Nevada river canyon, along with a few other rare local endemics. The plant was discovered in July, 1995, and described to science as a new species in 1996.
Physaria kingii is a species of flowering plant in the family Brassicaceae known by the common name King bladderpod. It is native to western North America from Utah to Baja California, where it grows in dry and rocky habitat, such as deserts and adjacent mountain slopes. This is a perennial herb growing a small, hairy stem from a caudex. The leaves form a patch or rosette around the caudex, each up to 6 centimeters long and round, oval, diamond, or spoonlike in shape. The inflorescence is an erect or mostly upright raceme of bright yellow mustardlike flowers. The fruit is a hairy capsule under a centimeter long suspended on a short, often curvy pedicel.
Malacothamnus mendocinensis is a species of flowering plant in the mallow family known by the common name Mendocino bushmallow. It is endemic to Mendocino County, California, where it is known from only two populations. It was presumed extinct until rediscovered in 2016 and now has a California Rare Plant Rank of 1B.1. In some treatments, Malacothamnus mendocinensis has been included within Malacothamnus fasciculatus or Malacothamnus hallii. Phylogenetic and morphological evidence, however, indicate that it is not closely related to these species and should be recognized as a separate species.
Malacothamnus parishii is a species of flowering plant in the mallow family known by the common name Parish's bushmallow. It is endemic to San Bernardino County, California, where it is confirmed from only a single collection from 1895. It has a California Rare Plant Rank of 1A. Malacothamnus parishii is currently treated as an extreme form of Malacothamnus fasciculatus var. laxiflorus. Phylogenetic analyses are needed to confirm whether it should be treated as a separate species or not.
