BIOLOGICAL COMMUNITIES

(continued)

A sizeable proportion of the species mentioned in the preceding paragraphs of this section are regularly found on and around limestone glades (or cedar glades; we use the terms interchangeably). In numbers of endemics, numbers of outcrops and in their aggregate area, cedar glades are best developed in the Nashville Basin of Middle Tennessee (Quarterman 1950). The characteristic cedar glade flora is also well established on glades found in northwestern Alabama and northwestern Georgia, as well as in some southeastern states more remote from Alabama, especially Kentucky, but also Virginia and West Virginia (Baskin and Baskin 1986, Bridges and Orzell 1986). Despite having many widespread calciphilic and/or xerophytic plant taxa in common, the Ketona Dolomite Glade flora is distinct from that of cedar glades, not only because of the endemic or other characteristic elements present in the Ketona Glade flora and absent from limestone glades, but conversely, by the sizeable number of endemic or characteristic elements of the limestone glade flora that are missing from the Ketona Glades. Cedar glade taxa occurring in both Middle Tennessee and northern Alabama that are absent or essentially so from the Ketona Glades include Allium cernuum Roth, Astragalus tennesseensis Gray ex Chapman, Astranthium integrifolium (Michx.) Nutt., Dalea gattingeri (Heller) Barneby, Delphinium carolinianum Walt. ssp. calciphilum Warnock [D. virescens auct. non Nutt.], Eurybia hemispherica (Alexander) Nesom [Aster hemisphericus Alexander], Grindelia lanceolata Nutt., Heliotropium tenellum (Nutt.) Torr., Hypericum dolabriforme Vent., H. sphaerocarpum Michx., Lobelia appendiculata A. DC. var. gattingeri (Gray) McVaugh, Oenothera triloba Nutt., Onosmodium molle Michx. ssp. molle,

Pediomelum subacaule (Torr. & Gray) Rydb., Ratibida pinnata (Vent.) Barnh., Rudbeckia triloba L. var. triloba, Sedum pulchellum Michx., Symphyotrichum priceae (Britt.) Nesom [Aster priceae Britt.], Talinum calcaricum Ware, Verbena simplex Lehm., and Viola egglestonii Brainerd.⁽¹⁾

Furthermore, the dominant grass species of the Ketona Glades is Schizachyrium scoparium, a perennial, while the dominant grass of cedar glades is Sporobolus vaginiflorus (Torr. ex Gray) Wood, an annual that is rarely found on Ketona Glades except in places disturbed by humans.

Baskin et al. (1994) attempted to resolve inconsistencies in the use of such terms as "glades," "barrens," and "limestone prairies" that have been used in discussing openings, dominated by grasses and forbs, that are developed over calcareous bedrock. They devised over a dozen criteria useful for assigning such places to one of three general categories: limestone glade, xeric limestone prairie, or barrens. The Ketona Glades fail several to many criteria for each of their three categories, but come closest to the "xeric limestone prairie" class. Since they differ from limestone prairies by developing over dolomite rather than limestone, by containing multiple endemics, and by supporting two species of Leavenworthia, the simplest course would be to establish a fourth category to accommodate the Ketona Glades.