On the top of the hill there is again a little Sclaginella, but the 

 areas between the bunches are mostly bare or with Boiiteloua, here 

 growing in short flat irregular tufts. Andropogon scopariiis ap- 

 pears in great abundance and becomes the most conspicuous mem- 

 ber of the consocies. Frequency counts were made here also, as 

 indicated by the numerals following the names. The ten bunch- 

 grasses present are as follows : 



Andropogon scopariits (lo) Paniaim pseiidopuhcscens (lo) 



Sorghastrmu nutans Stipa sparfca 



Leptoloma cognatum (7) Boutelona hirsitta (10) 



Panicuni perlongum (i) Koclcria cristata (10) 



Panicum Scrihneriamun Carer Muhlcnhcrgn 



Of these Andropogon scopariiis, Leptoloma cognatum, and Koe- 

 Icria cristata are the most important and are almost equally abun- 

 dant. The flat bunches of Panicuni pscudopuhcscens are very nu- 

 merous, but are inconspicuous among the larger bunches of the other 

 taller grasses. 



The ground is open, with probably 20 per cent, of the surface 

 exposed. The intervening spaces are bare or sparsely covered with 

 dead stems and leaves, or rarely with mats of Selaginella. This 

 permits a larger development of Panicuni pscudopuhcscens and the 

 interstitial vegetation, and the counts show that six of the seven in- 

 terstitials are frequent enough to appear in one or more of the 

 plots. Although the location is on top of a hill there is no evidence 

 of l)lowing. The secondary species are as follows. 



Perennials : 



Carcx festucacea, Accrates riridiflora, var. 



var. hrevior lanceolata 



Tradescantia reflexa Lithosperninm Gnielini (2) 



Pctalostcniuni pnrpurcum Aster sericcus (3) 



Lespedeza capitata (i) Aster linariifolius (6) 



Bnphorbia corollata (i) Solidago neinoralis (4) 



CcanotJius ovatus Helianthus scaberriiiius (4) 



Callirhoe iriangidata (4) Coreopsis palmata 



Hclianthcmuui ma jus Artemisia caudata (i) 

 Viola pedata 



Mats : 

 Selaginella rupestris (i) Opuntia Rafinesqmi 



