Amsonia hubrichtii, commonly known as Hubricht's bluestar, Arkansas bluestar, or thread-leaf bluestar, is a North American species of perennial flowering plant in the Apocynaceae (dogbane) family, first described in 1943. It is native to Oklahoma and Arkansas in the south-central United States. It is commonly used as an ornamental plant.
Amsonia tomentosa is a species of flowering plant native to the southwestern United States and northern Mexico (Chihuahua). Its common names include woolly bluestar and gray amsonia.
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.
Erysimum teretifolium is a species of Erysimum known by the common names Santa Cruz wallflower and Ben Lomond wallflower. It is a very rare plant endemic to Santa Cruz County, California, where it grows on inland sand spits, chaparral, and sandstone deposits in the southern Santa Cruz Mountains. It is a California state and federally listed endangered species.
Liatris cymosa, also known as Aggie-land gayfeather or branched blazing star, is a plant species in the family Asteraceae and genus Liatris. It is native to east central Texas in North America, where it is found in habitats such as post oak woodlands, fields, fence rows, woodland openings and edges, in clay soils. It blooms in mid to late summer with purple flower heads. It is of conservation concern due to habitat loss.
Plagiobothrys strictus is a rare species of flowering plant in the borage family known by the common name Calistoga popcornflower. It is endemic to Napa County, California, where it is known from only two small locations near Calistoga.
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.
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.
Eryngium pendletonense is a rare species of flowering plant in the carrot family known by the common name Pendleton button-celery. It is endemic to northern San Diego County, California, where it is known from four occurrences along the coastline between Oceanside and the Orange County border, including land within Camp Pendleton. It grows on vernally moist coastal grassland and coastal sage scrub habitat with clay soils. It was first described as a species in 1999.
Juncus digitatus is a rare species of rush known by the common name finger rush. It is endemic to Shasta County, California, where it is known from only two occurrences near Shingletown. It occurs in spring-moist habitat such as vernal pools in sunny locations in the foothills of the southernmost Cascade Range. The plant was first collected in 1991 and described to science as a new species in 2008.
Ambrosia cheiranthifolia is a rare species of flowering plant known by the common names South Texas ambrosia and Rio Grande ragweed. It is native to the coast of South Texas and the Mexican states of Tamaulipas and Coahuila. It occurs in coastal prairie, grassland, and mesquite shrubland habitat. It has declined because its native habitat has been cleared for development, with remaining open savanna invaded by non-native grasses such as buffelgrass. Today there are perhaps 20 populations remaining, but some of these may have very few genetic individuals because the species is clonal, with many cloned plants attached by one rhizome. It is not certain that the plant still exists in Mexico. This is a federally listed endangered species of the United States.
Amsonia kearneyana is a rare species of flowering plant in the dogbane family known by the common name Kearney's bluestar. It is native to Arizona, where there is only one native population in the Baboquivari Mountains of Pima County. There may also be a population just south of the border in Sonora, Mexico. The plant was federally listed as an endangered species in 1989. At that time the global population of the plant was made up of eight individuals in a riparian canyon. Since that time the plant has been manually propagated in an attempt to increase its numbers. Threats to the tiny native population include habitat destruction from livestock activity and flash floods in the river canyon. Many of the plants cannot reproduce because their seeds are sterile and nonviable, but this is probably due to insect predation on the seeds as they develop.
Cirsium vinaceum is a rare species of thistle known by the common name Sacramento Mountains thistle. It is endemic to Otero County, New Mexico, in the United States, where it is known only from the Sacramento Mountains. The plant can be found in six canyon systems in a southern section of this mountain range spanning about 32 kilometers. It is rare because it is limited to a specific type of mountain wetland which is both naturally uncommon and threatened by a number of forces. The plant was federally listed as threatened in 1987.
Erigeron rhizomatus is a rare species of flowering plant in the family Asteraceae known by the common names Zuni fleabane and rhizome fleabane. It is native to western New Mexico and eastern Arizona in the United States. It is a federally listed threatened species.
Eriogonum gypsophilum is a rare species of wild buckwheat known by the common names Seven River Hills buckwheat and gypsum wild buckwheat. It is endemic to the state of New Mexico in the United States, where it is known from only three sites in Eddy County. It is limited to a specific type of soil which is high in gypsum. The plant has been federally listed as a threatened species of the United States since 1981.
Potamogeton clystocarpus is a rare species of flowering plant in the pondweed family known by the common name Little Aguja pondweed. It is endemic to Texas in the United States, where it is known only from one river canyon in Jeff Davis County. There is a single population of the aquatic plant in Little Aguja Creek, and it has never been seen anywhere else. This is a federally listed endangered species of the United States.
Solidago houghtonii is a rare North American species of flowering plant in the family Asteraceae known as Houghton's goldenrod. It is native to southern Ontario, Canada and the northern United States. It is threatened by the loss and degradation of its habitat. It is a federally listed threatened species of the United States and it is designated a species of special concern by Canada's Committee on the Status of Endangered Wildlife in Canada.
Thymophylla tephroleuca is a rare species of flowering plant known by the common names ashy pricklyleaf and ashy dogweed. It is endemic to Texas in the United States, where it occurs in two counties near the Mexican border. It became rare due to the destruction and degradation of its habitat. It is a federally listed endangered species of the United States.
Physaria thamnophila is a rare species of flowering plant in the mustard family known by the common name Zapata bladderpod. It is native to Texas in the United States, where it is known from Zapata and Starr Counties. The plant is threatened by the loss and degradation of its habitat. It is federally listed as an endangered species.
Amsonia jonesii is a plant in the bluestar genus Amsonia known by the common name Colorado desert bluestar. It is in the dogbane family, but a separate genus. It grows in the deserts surrounding the Colorado River in the United States. It is now grown as a garden plant for its masses of light blue flowers and low water usage.
