A calcareous glade is a type of ecological community that is found in the central Eastern United States. Calcareous glades occur where bedrock such as limestone occurs near or at the surface, and have very shallow and little soil development. Due to the shallow soil and the extreme conditions created by it, trees are often unable to grow in the glades. This creates a habitat that is usually sunny, dry, and hot. Calcareous glade vegetation is more similar to that of a desert habitat than a grassland, being dominated by small spring annuals with occasional geophytic or succulent perennials.
Eriogonum longifolium var. harperi, also known as Harper's buckwheat or Harper's umbrella plant, is a dicot of the family Polygonaceae, found in areas of nutrient-poor shale soils in Alabama, Kentucky and Tennessee. It lives inconspicuously in an immature vegetative stage for four or more years before developing a flowering stalk, then flowers and dies. It is listed as an endangered species by the state of Tennessee. It has eleven small populations in Alabama and five in Tennessee but its survival in Kentucky is uncertain. According to a leading expert, Professor James L. Reveal of the University of Maryland, its Kentucky population has been reportedly extirpated. Its 2006 Alabama Natural Heritage Program ranking was G4T2S1, demonstrating an opinion that it was "critically imperiled" in that state.
Brodiaea filifolia, known by the common name threadleaf brodiaea, is a rare species of flowering plant in the cluster-lily genus. It is endemic to southern California, mostly in the region around the junction of Orange, Riverside, and San Diego Counties.
Paysonia lescurii is a species of flowering plant in the family Brassicaceae known by the common names Lescur's bladderpod or Nashville mustard. It is native to Middle Tennessee, where it can be found in wet fields, lawns, and roadsides. It is also present in neighboring areas of Kentucky and Alabama.
Dalea foliosa, commonly called leafy prairie clover, is a species of flowering plant in the legume family (Fabaceae). It is an endangered species in the United States, where it occurs in three states: Illinois, Tennessee, and Alabama.
Cladonia perforata is a rare species of lichen known as Florida perforate cladonia and Florida perforate reindeer lichen. It is endemic to the state of Florida in the United States, where it is known from 16 populations in four widely separated areas of the state. It is native to a very specific type of Florida scrub habitat which is increasingly rare and patchy due to habitat destruction, degradation, and fragmentation. In 1993 this was the first species of lichen to be federally listed as an endangered species of the United States.
Crotalaria avonensis is a rare species of flowering plant in the legume family known by the common names Avon Park rattlebox, Avon Park harebells, and Avon Park rabbit-bells. It is endemic to Central Florida in the United States, where it is known from only three sites. Many individuals exist on land that is unprotected and they are threatened with destruction. The plant is a federally listed endangered species.
Paysonia lyrata is a rare species of flowering plant in the family Brassicaceae known by the common name lyreleaf bladderpod. It is endemic to Alabama in the United States, where it is known from only three occurrences. It is federally listed as a threatened species.
Lomatium cookii is a rare species of flowering plant in the carrot family known by the common names Cook's lomatium and agate desertparsley. It is endemic to Oregon in the United States, where it grows in only two valleys. It is a federally listed endangered species.
Physaria filiformis is a rare species of flowering plant in the family Brassicaceae known by the common names Missouri bladderpod and limestone glade bladderpod. It is native to Missouri and Arkansas in the United States. It was federally listed as an endangered species in 1987 and it was downlisted to threatened status in 2003. P. filiformis remains listed as an endangered species at the state level in Missouri.
Physaria obcordata is a rare species of flowering plant in the family Brassicaceae known by the common name Dudley Bluffs twinpod. It is similar in appearance to the more common Piceance twinpod, but can be distinguished by looking at the leaves through a hand lens. The Piceance twinpod, Physaria acutifolia has stellate hairs when viewed through a hand lens while Physaria ocordata has markings that look like a satellite dish, or a circle with a dot in the middle. It is endemic to Colorado, where it is found only in the Piceance Basin in Rio Blanco County. It is threatened by the loss and degradation of its habitat. It is a federally listed threatened species of the United States.
Physaria globosa is a rare flowering plant in the mustard family commonly known as globe bladderpod, Short's bladderpod, and Lesquereux's mustard. It is endemic to the United States, where it is limited to Indiana, Kentucky, and Tennessee. It is a rare species throughout its range and in 2014 the U.S. Fish and Wildlife Service issued a final rule protecting it under the Endangered Species Act.
Physaria parviflora is a species of flowering plant in the family Brassicaceae known by the common names Piceance bladderpod and frosty bladderpod. It is endemic to Colorado in the United States, where it occurs in Garfield, Mesa, and Rio Blanco Counties.
Paysonia stonensis is a species of flowering plant in the family Brassicaceae, known by the common name Stones River bladderpod. It is endemic to Tennessee in the United States, where it is limited to Rutherford County. It grows only in the floodplains of the Stones River, and certain tributaries.
Leavenworthia crassa is a species of flowering plant in the mustard family, Brassicaceae, known commonly as the fleshy-fruit gladecress. It is endemic to Alabama in the United States, where it occurs in only two counties. It is "likely one of the most imperiled plant species in the Southeast," and the United States Fish and Wildlife Service issued a final rule listing it as an endangered species in 2014.
Physaria pallida is a rare species of flowering plant in the mustard family known by the common name white bladderpod. It is endemic to Texas in the United States, where it is known only from San Augustine County. It is federally listed as an endangered species.
Physaria congesta is a rare species of flowering plant in the mustard family known by the common name Dudley Bluffs bladderpod. It is endemic to western Colorado in the United States, where it is known only from seven occurrences in Rio Blanco County. It is federally listed as a threatened species.
Physaria pruinosa is a species of flowering plant in the family Brassicaceae known by the common names Pagosa Springs bladderpod and frosty bladderpod. It is native to Colorado and New Mexico in 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.
Physaria tumulosa is a rare species of flowering plant in the family Brassicaceae known by the common name Kodachrome bladderpod. It is endemic to Utah in the United States, where it is known only from Kane County. There is only one known population of this plant made up of scattered occurrences totalling about 20,000 individuals, all within the Kodachrome Basin. The plant is threatened by the loss and degradation of its habitat. It is federally listed as an endangered species. It was previously treated as a subspecies of Physaria hitchcockii.
