58 



circular patches one to three feet ( 

 conspicuous because of their gray 

 species are the following". 



3-10 dm.) across, which are very 

 color. The principal secondary 



Bunch-grasses : 

 Sorghastniin nutans 

 Panicnm virgatum 

 Panicuni pseudopuhescens 



Perennials : 

 Tradescantia reflexa 

 Amorpha canesccns 

 Petalostcnium candidum 

 Petalostcniuni pur pur cum 

 Tephrosia lirglniana 

 J'^iola pedata 

 CallirJwe triangulata 

 Lithospcruunn Gniclini 



Mats : 



Sclaginclla rupcstris 

 Opttntia Rafinesquii 



Interstitials : 

 Fcstuca octo flora 

 Rumex AcetoscUa 

 Lepidium virgin icuin. 

 Arabis lyrata 



Panicnm perlongum 

 Stipa spartea 



Pcntstcuwn hirsutus 

 Solidago nemoralis 

 Aster s eric ens 

 Aster linariifolius 

 Hclianthus scabcrr'un U' 

 Coreopsis palmata 

 Artemisia caudata 



Opuntia fragilis 

 Antennaria sp. 



O.ralis corniculata 

 Scutellaria parvnla 

 Monarda punctata 

 Ambrosia psilostacJiya 



The vernal aspect is characterized by the blue flowers of Viola 

 pedata, which were still in bloom when the consocies was first vis- 

 ited in June; later, Pentstemon hirsutus and Lithospermum Gmelini 

 are conspicuous with their white and yellow flowers. The aestival 

 season is \^•ell markd by Tradescantia reflexa, and the serotinal by 

 Monarda punctata, which is frequently present in immense numbers. 

 The flowers of the prairie clovers (Petalostenitun), the lead plant 

 (Amorpha canescens), and the sand poppy {Callirhoe) appear at 

 the same season, but the plants are usually too scattered to break the 

 effect of the masses of Monarda. Still later, in the autumnal aspect, 

 the prevailing tone is yellow from the flowers of the goldenrod, 

 Solidago nemoralis. 



The Koeleria cristata consocies illustrates well the general prin- 

 ciple that an association may be derived from different sources. In 



