64 ECONOMIC BOTANY OF ALABAMA. 



4. The Blue Ridge. 



(Figures 19, 20.) 



This begins in Pennsylvania, has its greatest develop- 

 ment in a complex mountain system in western North 

 Carolina, and tapers out in Alabama. In this state it com- 

 prises a single ridge with a few spurs branching off to 

 the southeastward, and a few isolated peaks and ridges 

 in the edge of the Coosa valley northwestward. The to- 

 tal area to be included in this region is uncertain on ac- 

 count of the vagueness of its southeastern boundary, but 

 it is probably not more than 400 square miles. 



References.— Harper 7, Mohr 6 (73), Mohr 8 (59-65), 

 Reed (7-8, 9-10, 27-28), Smith 1 (37-43, 58-75), Smith 6 

 (87-88, 92, 100), Smith 7 (348-349, 361, 383), Smith 9 

 (6-7). 



Geology and soils. — The main body of the Blue Ridge 

 consists of metamorphic rocks, presumably mostly pre- 

 Cambrian, though some of the strata must be much 

 more recent, for Carboniferous fossils have been found 

 at the southeastern base of the ridge in Clay County, ac- 

 cording to Dr. Smith. t The outlying peaks and ridges 

 lying to the northwestward, in Calhoun and Talladega 

 Counties, are Cambrian (Weisner quartzite), but do not 

 differ perceptibly in soil or vegetation from the meta- 

 morphic mountains. The rocks on all these mountains 

 (as on many other southern mountains of various ages) 

 are mostly sandstone, and there is comparatively little 

 soil, but what little there is is rather sandy. 



Topography and hydrography. — The Blue Ridge in- 

 cludes the highest mountain in Alabama (Cheaha, 2,400 

 feet above sea-level) , and many peaks and ridges as high 

 as 2,000 feet, or over 1,000 feet above the adjacent Coosa 

 valley. The difference of elevation on the southeastern or 

 Piedmont side is almost as great, so that from the main 

 ridge on a clear day one can see in either direction as far 

 as the curvature of the earth will allow.* The slopes of 



tScience 11.18:244-246. Aug. 21, 1903. 



*There are no higher peaks in sight from which to estimate dis- 

 tance, but the view from Cheaha must embrace at least 10,000 

 square miles. 



