Pleurochaete squarrosa (Brid.) Lindb. New to Mississippi, and Extensions of Its Range in Alabama

Abstract

Pleurochaete squarrosa (Brid.) Lindb. is reported for the first time for Mississippi and significant range extensions for it are reported for Alabama. The distribution ofPleurochaete squarrosa (Brid.) Lindb. in the United States includes Virginia, Geor- gia, Alabama, Arkansas, Missouri, Oklahoma, Tex- as, New Mexico, and Arizona (Crum & Anderson 1981). It typically occurs on thin soil over exposed limestone of cedar glades (Quarterman 1956), but also occurs on outcrops of sandstone (Redfearn 1972) and granite (Whitehouse & McAllister 1954; Wyatt & Stoneburner 1982). Pleurochaete squarrosa is here reported for the first time for Mississippi. It is not unexpected that the species occurs in Mississippi since the east cen- tral portion of the state has surface geological fea- tures typical of the habitat of P. squarrosa, i.e., lime- stone cedar glades. The Mississippi localities include Oktibbeha, Noxubee, and Lowndes counties, all of which lie in the Black Prairie Belt region of the Gulf Coastal Plain Province. Juniperus virginiana L. is the most abundant woody species of the limestone glades, which characterize the Black Prairie Belt re- gion of Mississippi. In Oktibbeha County, P. squar- rosa grows abundantly beneath J. virginiana in par- tial shade in an area approximately 30 x 15 m. Here it represents the dominant herbaceous vege- tation. In Noxubee and Lowndes counties it appar- ently is more scattered and not nearly as abundant. An attempt to locate sporophytes over a three year period was unsuccessful. As pointed out by Quar- terman (1956), vegetative propagation is probably responsible for the success and abundance of the species in appropriate habitats. Soil samples from each county collection site in- dicate a basic substrate for all sites with a pH range of 8.5-9.0. This is considerably more basic than the pH of 6.1 for a granite outcrop in east central Al- abama reported by Wyatt and Stoneburner (1982). Pleurochaete squarrosa (Brid.) Lindb., therefore, ap-