245 



and the first cotton field was seen a few minutes later. The 

 correlation between the distribution of these two things is re- 

 markably close in some places. 



Pinus echinata was first seen about ten miles southwest of 

 Bristol, in Tennessee, but did not become abundant until about 

 fifty miles farther on. It would appear from the map in Mohr's 

 "Timber pines of the southern United States" (U. S. Forestry 

 Bulletin 13) that it extends much farther north in the mountains 

 to the westward than in the Appalachian Valley. 



Pinus Strohus, occasional in Virginia, was last seen about 45 

 miles southwest of Bristol. It barely overlaps P. echinata, and 

 on this route does not grow anywhere near P. Taeda. One 

 might suppose from the gap between their ranges that there is a 

 climatic barrier between P. Strohus and P. Taeda, but I have seen 

 them growing side by side at the western base of the Cohutta 

 Mountains in Murray County, Georgia. 



Tsuga Canadensis has a distribution and habitat much like 

 that of Pimis Strohus, but on this route it was seen only about 

 half as often. Sometimes it was accompanied by Rhododendron 

 maximum, especially in the sandstone country near Pulaski, Va. 



Thuya occidentalis was seen twice on rocky bluffs in Smyth 

 County, Virginia. 



Spathyema foetida was seen a few times in Wythe and Washing- 

 ton Counties, Virginia, and Caltha palustris in Wythe and Smyth. 

 I do not remember ever seeing either farther south, although they 

 are supposed to grow in the mountains of North Carolina. 



Fagus grandifolia was seen only a few times, and Betula nigra 

 not at all. 



Phoradendron flavescens was noted only once, that in Greene 

 County, Tennessee. 



Liquidamhar is rare north of Knoxville, but very common in 

 Alabama. 



Fragaria was the commonest weed recognized along the right- 

 of-way in Virginia, and Lonicera Japonica in Tennessee. 



Acer saccharinum was observed only In Tennessee, along the 

 Holston and Tennessee Rivers. 



