Pound and Clements: METHOD OF DETERMINING SPECIES. 21 



(2) 

 Amorpha cancsccns ...... -268 



Aster multijlorus ....... -205 



Antennaria campestris (6 patches) . . . 154 

 SoUdago rupestris . . . . . . .105 



Ifelianthus rigidus ...... 63 



Kuhnistcra Candida ...... 26 



Kuhnistera purpurea . . . . . . 22 



Brauneria pallida . . . . . . 10 



Solidago rigida . . . . . . .16 



Rosa arkansana ....... 8 



SoUdago rigidiuscula ...... 5 



Gerardia purpurea ...... 3 



Laciniaria scariosa ....... 2 



Erlgcron ramosus ...... i 



Linum rigidum was prominent, but did not occur in either of 

 the plots, and in comparatively few of those laid out. 



In a large number of plots, Amorpha canescens averaged 309, 

 Aster multijlorus 275, and Antennaria campestris 12 patches 

 and 145 individuals. 



Enumerations were also made in the same formation in the 

 transition area between the prairie region and the sand hill re- 

 gion. The following example is one of a number made south 

 of Broken Bow (Custer County). The formation is the ordi- 

 nary prairie grass {Sporobohis-Koeleria-Panicum) formation, 

 modified somewhat on account of the sandy soil. 



Amorpha canescens . , . . . 291 

 Aster multijlorus ....... 238 



Kuhnistera Candida (?) . . . . . 23 



Solidago rupestris . . . . . . .21 



Brauneria pallida . . . . . . 17 



Helianthus rigidus . . . . . . .12 



Kuhnia glutinosa ...... 5 



The marked decrease in the number of secondary species and 

 in the abundance of each is characteristic of this transition area. 



Another count, made where the prairie grass formation was 

 giving way to the buffalo grass formation on the one hand, and 

 to the bunch grass formation on the other, is interesting. 

 While the prairie grasses (species of Sporobolus, Koeleria cris- 

 tata and Panicum Scribnerianuni) were controlling, there was 

 a strong admixture of Bouteloua oligostachya, and two bunches 



