14 BOTANY OF MADISON, LINCOLN, GARRARD, 



Black Slate. — The Black Slate through this region has 



several phases — one where the shale is level and not well 

 drained, and the other where are well drained slopes. The 

 first had many glad)' places with small trees of white oak, red 

 oak, black oak, laurel oak, and post-oak. The last was well 

 defined, with a beech forest, in which some white oak, poplar, 

 red oak, and other species grew. Sweet gum, in patches here 

 and there, was a common tree. 



Lower SubcarbOIliferOUS. — This formation, which con- 

 stitutes nearly the. whole surface of the so-called Knobs, which 

 lie on the south side of this region, is well outlined in all the 

 counties of the district, with the exception of Washington. 

 The soils were not valuable lor the better purposes o( agri- 

 culture; but they possessed a great variety of trees, many val- 

 uable species growing to good size and desirable qualities. 

 With the exception of the top of Big Hill, and one or two 

 other high points in Madison county, pines, chestnut, moun- 

 tain chestnut oak, sour-wood, laurel, and some other species, 

 were exclusively confined to those soils. Fine poplar, white 

 oak, white ash, black gum, white hickory, walnut, maple, and 

 basswood were everywhere. Besides those, main- shrubs, 

 vines, and flowers were restricted alone to these soils. 



Upper Subcarboniferous. — The limestones of the 



upper part of the Subcarboniferous group make several 

 classes of soils, but they are restricted in their development 

 here, and do not, as a consequence, give much latitude for an 

 investigation of the peculiarities of the plant life over them. 

 White oak, red oak, scarlet oak, black jack oak, Spanish oak, 

 post-oak, walnut, hickory, ash, and poplar were the principal 

 trees. The black jack oak was nearly confined to this geo- 

 logical horizon ; the scarlet oak was rarely seen away from it, 

 but the cedar was distributed over the more exposed beds 

 of heavy limestones. 



Coal Measures.— The restricted areas, where remains of 

 the conglomerate sandstones and the carboniferous shales had 



