THE BOTANY OF ARKANSAS. 247 



It appears certain, then, that the moulding influence, in this 

 case at least, lies in the character of the soil. That action of 

 the soil, however, which produces the above stated effects, may 

 be either mechanical or chemical. It is to be noted, too, that 

 the plants mentioned above as abundant on the limestone occur 

 also abundantly in alluvial soil, and it is probably true that 

 each one of these species has been found in other localities on 

 both sandstone and limestone. 



It appears, then, that under the same climatic conditions, the 

 kind of soil materially effects the distribution of plants ; cer- 

 tain species, while not absolutely requiring a particular soil, at 

 least prefer it, and upon it stand a much better chance of sur- 

 vival.* 



ECONOMIC NOTES. 



Grazing plants. — Among the plants of economic value, 

 Lespedeza striata, " Japanese clover," is worthy of especial 

 notice. It is evidently a Lespedeza, though it does not agree 

 with any of our described species. 



According to the reports current among farmers, the plant 

 was first seen in abundance from five to ten years ago. Whether 

 then introduced or indigenous, they did not know. A gentle- 

 man informs me that the plant is also found abundantly in 



*To Professor Coville's results we have to add the observations made by Dr. J 

 Francis Williams in studying the geology of Magnet Cove in Hot Spring county. 

 Dr. Williams' work has been upon the geology of the eruptive rocks, and he finds it 

 a rule with scarcely an exception that the pine does not grow upon soils derived from 

 eruptive rocks, though it is very abundant in the adjacent areas of sedimentary rocks. 

 See An. Rep. Geol. Survey of Ark., for 1890, Vol. n. 



Such cases have fallen under my own observation in several places in the State, 

 but I have usually found that the effect of soil upon tree growths manifests itself in 

 the number of individuals present, rather than in the simple presence or absence of 

 species. In Vol. II, pp. 56-57, of the Reports for 1888, Professor Hill has referred 

 to the preference of the pine of southwest Arkansas for the Tertiary and Post-ter- 

 tiary soils. The predominance of pine in the case he refers to is very marked, though 

 pine is not confined to those geologic formations. It is simply a difference in quan- 

 tity, but one which amounts to as sharp a division line as that between such colors 

 as black and gray. — J. C. Branxer. 



