310 botanical gazette. [December, 



i 



The relation of the flora to the geological formations in Lincoln 



county, Kentucky. 



HARRY A. EVANS. 



"as 



T 



All farmers recognize the relation existing between the 

 timber and the soil (which must result in most cases from the 

 underlying rock), as is evident from the expressions which 

 they use in speaking of the quality of land, such as " walnut 

 land," »« white oak land," " beech land " and " ash land, __ 

 Henry Clay called his place from the abundance of ash trees 

 which grew upon it. This relation is constantly forced on 

 the collector's notice, and especially is this the case where the 

 territory collected over has a number of formations repre- 

 sented. In this (Lincoln) county there are some twent) 

 formations, all but two of which are of such surface extent as 

 to give rise to characteristic soils. 



Last summer I made as complete a list as was possible of 

 the flowering plants occuring on each of these formations, 

 taking care to include no plant which seemed to owe its po- 

 sition to the elevation or moisture of an)' formation, rather 

 than to the character of the soil. Similar formations in the 

 surrounding counties were examined, and the list corrected 

 by dropping the names of any plants which were not com- 

 mon to each horizon in all of its exposures. (In the case of 

 the Chazy, Birdseye and Upper Subcarboniferous this was 

 not done.) 



From this list, thus corrected, I have tried to determine 

 the species which prefer, or are peculiar to, each of the for- 

 mations in this county. Whether the results, as given in 

 this article, will hold good for other localities I do not know ; 

 if they do not it will show that the position of the plants here 

 is due to some condition of exposure, elevation or moisture, 

 and not to the character of the soil. I hope that collectors 



in states where the formations here given occur will test the 

 results. 



Most of the plants which are mentioned on only one for- 

 mation I have never found on anv other : with one exception 

 no plant is mentioned if onlv a small number of specimens ol 

 it have been observed. 



Chazy.— The Chazy limestones, 225 feet in thickness. 



ire seen in this state only on the Kentucky and Dix rivers, 



near the mouth of the latter. They form the base of the high 



