250 A NATURALIST IN THE GREAT LAKES REGION 



conspicuous, replacing in part the above-mentioned forms. 

 On thin-soiled prairie, or prairie with sandy soil, the pink and 



FIG. 368. Wild onion in blossom, Allium cernuum 



white prairie clover, Petalo sternum (Fig. 377), and lead plant 



(Fig. 378) are apt to predominate, while such typical plants of 



the clay-soil prairie 



as Silphium terebin- 



thinaceum, S.lacinia- 



tum, and Eryngium 



yuccifolium are 



rare. 



Naturally in any 

 region with as dis- 

 tinctive a group of 

 plants as exists in 

 the prairie there will 



. . FIG. 369 FIG. 370 



FIGS. 369, 370: Fig. 3 6 9 .-Culver's root, Veronica 

 Assemblage of mrginica; Fig. 370. Golden old man, Zizia aurea. 



