IO BOTANY OF MADISON, LINCOLN, GARRARD, 



prickly wild gooseberry, white enslcnia, corky white elm, or 

 the wall-rue spleenwort. The latter we have observed many 

 times, and always as occupying- a station on a single heavy 

 layer of limestone, following its dip up or down the river, but 

 never growing on other ledges. 



Birdseye Limestones. — This group, like the last, is 



seen only near the streams mentioned, making some few soils, 

 but covered sparsely with trees other than the red cedar. 

 This tree still grows in immense numbers and of the finest 

 quality, single specimens having been seen twenty-eight to 

 thirty inches in diameter. The peculiar home ol the cedar 

 seems to be on the limestone soils, and the purity of the 

 Birdseye series seems to bring it to its greatest perfection. 



Trenton Limestones. — The Trenton Limestones, in 

 their different classes of soil-making rocks, had distributed 

 over them different associations of plants. Over the deep 

 silicious clay soils peculiar to the base of these rocks white 

 oak, yellow poplar, and beech were the principal species, 

 giving out in a large measure, however, when these aluminous 

 soils gave place to either the Birdseye group below or the 

 Blue Grass beds above. Measured by their general distri- 

 bution here, none of the above-mentioned trees are well 

 adapted to calcareous soils, but, on the other hand, require 

 clay soils, which contain a proportion of silicious elements. 

 The old people of the country tell of the remarkable belts 

 of white oak, beech and poplar, which originally grew over 

 some parts of these counties now denuded of forests. These 

 areas can yet be outlined by the character of the small wood- 

 lands not yet destroyed and by the extension of the soils on 

 which they grew. 



Over the Blue Grass beds, the forests were particularly 

 marked with blue-ash, white elm, white chestnut-oak, maple, 

 wild cherry, basswood, coffee-tree, large-fruited shell-bark hick- 

 ory, hackberry, and mulberry. A variety of other trees grew 

 with them, but not often in great numbers. The blue-ash and 

 wild cherry sometimes made up fifty percent, of the trees. These 



