Calcareous glade

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.

The usage of the words "glades" and "barrens" to describe dry, rocky communities in the United States is not uniform, and the terms are often used interchangeably.

Outside of the Central Basin, calcareous glades are found in lower numbers throughout the Interior Low Plateau, and species endemism is greatly reduced.

The name comes from the abundance of eastern red cedar (Juniperus virginiana) that occurs on the margins of the glades or in cracks in the bedrock where the roots can gain a foothold.

Many of the characteristic plants that grow in the limestone glades of the Central Basin are endemics that occur nowhere else, or disjunct populations of plants that are widespread in the prairies of the central U.S.[3] Some species with highly restricted ranges that occur in the glades of the Central Basin include the Tennessee coneflower (Echinacea tennesseensis), Pyne's ground plum (Astragalus bibullatus), leafy prairie clover (Dalea foliosa), Tennessee milkvetch (Astragalus tennesseensis), Nashville breadroot (Pediomelum subacaule), and limestone fameflower (Phemeranthus calcaricus).

[1] Species indicative of Ozarkian calcareous glade communities include Cheilanthes feei (slender lip fern), Echinacea simulata (pale purple coneflower), Heliotropium tenellum (pasture heliotrope), Isoetes butleri (limestone quillwort), Oenothera macrocarpa (Missouri evening primrose), and Ophioglossum engelmannii (limestone adder's-tongue).

[9] Endemic species of this area include Castilleja kraliana, Dalea cahaba, Liatris oligocephala, Lithospermum decipiens, and Spigelia alabamensis.