Threatened flora of California

Holocarpha macradenia, commonly known as the Santa Cruz tarplant, is an endangered plant endemic to Northern California.

Acanthomintha ilicifolia, known by the common name San Diego thornmint, is a rare species of flowering plant in the mint family.

Allium tribracteatum, known by the common name Threebract onion, is a species of wild onion found in California.

Allium yosemitense is a California species of wild onion known by the common name Yosemite onion.

Packera layneae, known by the common name Layne's ragwort and Layne's butterweed, is a rare species of flowering plant in the aster family.

Erigeron parishii is a species of flowering plant in the daisy family known by the common name Parish's fleabane.

Leptosiphon ambiguus (syn. Linanthus ambiguus), the serpentine linanthus, is a low annual plant with needle-like leaves and a vivid lavender flower.

Salix exigua (sandbar willow, narrowleaf willow, or coyote willow; syn. S. argophylla, S. hindsiana, S. interior, S. linearifolia, S. luteosericea, S. malacophylla, S. nevadensis, and S. parishiana) is a species of willow native to most of North America except for the southeast and far north, occurring from Alaska east to New Brunswick, and south to northern Mexico.

Orcuttia tenuis (slender Orcutt grass) is a species of grass which is endemic to northern California.

Orobanche vallicola is a species of broomrape known by the common name hillside broomrape.

Quercus pacifica is a species of oak known by the common names island scrub oak, Channel Island scrub oak, and Pacific oak.

Navarretia fossalis is a rare species of flowering plant in the phlox family known by the common name spreading navarretia.

Euphorbia hooveri is a species of euphorb known by the common names Hoover's sandmat and Hoover's spurge.

Castilleja cinerea is a species of Indian paintbrush known by the common name ashgray Indian paintbrush.

Ceanothus ophiochilus is a rare species of flowering shrub known by the common name Vail Lake ceanothus, native to Southern California.

Clarkia springvillensis is a rare species of flowering plant in the evening primrose family known by the common name Springville clarkia.

Dudleya nesiotica is a very rare succulent plant known by the common name Santa Cruz Island liveforever.

Dudleya verityi is a rare species of succulent plant known by the common name Verity's liveforever.

Trichostema ovatum is an uncommon species of flowering plant in the mint family known by the common name San Joaquin bluecurls.

Triphysaria floribunda is a rare species of flowering plant in the broomrape family known by the common name San Francisco owl's-clover.

Arenaria ursina is a species of flowering plant in the pink family known by the common name Bear Valley sandwort.