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. Because of 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.
Ceanothus ferrisiae is a rare species of shrub in the family Rhamnaceae. Its common name is coyote ceanothus.
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.
Campanula robinsiae is a rare species of flowering plant in the bellflower family known by the common names Brooksville bellflower, Robins' bellflower, and Chinsegut bellflower. It is endemic to Florida, where it is known from four or five occurrences in Hernando and Hillsborough Counties. Its population has fluctuated throughout the years; at one point in the early 1980s it was feared extinct. Today there are two populations in Hernando County and probably three in Hillsborough River State Park. At the time the plant was listed as an endangered species of the United States in 1989, it was known from three small populations on wet prairies that were threatened by changes in the local hydrology and by pollution. It was also thought to be threatened by vandalism, trampling, and collecting by flower enthusiasts. Cattle grazing and invasion of the habitat by the exotic skunkvine also degrade the habitat.
Jacquemontia reclinata is a rare species of flowering plant in the morning glory family known by the common names beach clustervine, reclined clustervine, and beach jacquemontia. It is endemic to the southeastern coast of Florida, mainly within the South Florida metropolitan area, in the United States, where little of its native habitat remains. It is a federally listed endangered species.
Paysonia perforata, known by the common name Spring Creek bladderpod, is a rare species of flowering plant in the mustard family. It is endemic to Tennessee in the United States, where it is known only from Wilson County. This very rare plant is threatened by the loss and degradation of its habitat. It is federally listed as an endangered species.
Lupinus aridorum is a rare species of lupine known by the common name scrub lupine. It is endemic to Florida in the United States, where there were 10 known populations remaining in 2003. Fewer than 6000 individual plants were counted. It is threatened by the loss and degradation of its habitat. The scrub lupine is a federally listed endangered species of the United States.
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.
Spigelia gentianoides is a rare species of flowering plant in the Loganiaceae known by the common names purpleflower pinkroot and gentian pinkroot. It is native to Alabama and Florida in the United States, where a few small populations remain. It is threatened by the loss and degradation of its habitat, and is a federally listed endangered species of the United States.
Clinopodium dentatum is a species of flowering plant in the mint family known by the common names toothed savory and Florida calamint. It is native to Florida and Georgia in the United States.
Euphorbia purpurea is a species of Euphorbia known by the common names Darlington's glade spurge, glade spurge, and purple spurge. It is native to the eastern United States, where it occurs from Ohio and Pennsylvania south to North Carolina. It has been extirpated from Alabama; it was believed lost from Delaware until a population was rediscovered in 1997.
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.
Matelea alabamensis is a species of flowering plant in the dogbane family known by the common names Alabama milkvine, Alabama anglepod, and Alabama spiny-pod. It is native to the southeastern United States, where it occurs in Alabama, Georgia, and Florida.
Leavenworthia crassa is a species of flowering plant in the 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.
