6 NATIVE LEGUMES IN NEBRASKA AND KANSAS. 



Tlio corresponding data for 1908 are as follows: 



33:^ Psoralea, found on 9 out of the 14 plats. 

 185 Amorpha, found on 8 out of the 14 plats. 

 340 Kuhnistera, found on 8 out of the 14 plats. 

 12 Astragalus, found on 4 out of the 14 plats. 



77 Vicia, found on 3 out of the 14 plats. 

 57 Lotus, found on 4 out of the 14 plats. 



3 Aragallus, found on 1 out of the 14 plats. 



1 Baptisia, found on 1 out of the 14 plats. 



4 Lespedeza, found on 1 out of the 14 plats. 



The vai'iation in the relative numbers of representatives of different 

 genera found in the two seasons is due largely to the fact that the ma- 

 jority of counts made in 1908 w^ere on the rolling lands of southeastern 

 Nebraska and in 1909 on the level prairies of the south-central part 

 of the State. On the hills, Kuhnistera is much more abundant than 

 on the level land and Psoralea is represented mostly by Psoralea 

 JJorihunda, which is a very large plant, and hence the individuals are 

 not very numerous when compared with the smaller, more gregarious 

 P. argoyliyUa, which is almost the sole representative of the genus 

 on the more level prairies of south-central Nebraska. This plant 

 often forms dense patches (not, however, excluding the grasses), 

 which cover a very large proportion of the prairie, giving the whole 

 a silvery cast. 



Combining the figures for the two years we have the following 



totals: 



3,308 Psoralea, found on 29 out of the 3G plats. 

 704 Amorpha, found on 22 out of the 36 plats. 

 521 Kuhnistera, found on 17 out of the 36 plats. 

 151 Astragalus, found on 17 out of the 36 plats. 

 637 Vicia, found on 9 out of the 36 plats. 

 123 Lotus, found on 7 out of the 36 plats. 

 ' 21 Aragallus, found on 4 out of the 3() plats. 

 6 Baptisia, found on 4 out of the 36 plats. 



78 Lespedeza, found on 4 out of the 36 plats. 

 10 Morognia, found on 1 out of the 36 plats. 



2 Meihomia, found on 2 out of the 36 plats. 



RELATIVE IMPORTANCE OF THE DIFFERENT GENERA. 



The nujnbcr of plants of the first four genera, at least, and the 

 number of plats on which they were found probably give a fair idea 

 of the relative importance of the representatives of these genera as 

 nitrogen gatlierers, especially when considered in connection with the 

 sizes of the plants. It is certain that they are not nil equally efficient 

 in this work, but on this point no information is available. The 

 large numbers of Psoraleas and their wide and comparatively uniform 

 distribution, as shown by these figures, make them stand out strik- 

 ingly as the most important of tlio group. The other genera are 

 much less important than the first four. 



[Cir. 70J 



