BIG SPRING PRAIRIE. 17 



usage. On account of the more abundant opportuni- 

 ties for artificial or accidental seed dissemination along 

 highways, these latter societies possess a greater vari- 

 ety of plant life than fence-rows away from highways. 

 The most successful roadside plants are those, which, 

 when broken or cut oflf, have the power of sprouting 

 up from the stub or root. These sprouts are generally 

 quite prolific in seed production. It is also of advan- 

 tage for these plants to possess a perrennial under- 

 ground rootstock as many of them do. The inequali- 

 ties in the level of a cross-section of the average coun- 

 try pike or road furnish conditions for extremely varied 

 sub-divisions in Roadside societies. 



The traveled roadbed is extremely xerophytic, the 

 ditch or depression commonly occurring may support a 

 hydrophytic society, while the remainder of cross- 

 section may offer narrow beds of xero-mesophytic, and 

 mesophytic, and hydro-mesophytic. Thus all forms of 

 plant societies may exist in duplicate on each side of a 

 road not over fifty to sixty feet in width. On account 

 of the frequent rock outcrops, the roadways of the 

 Ridges are more evenly xerophytic or xero-mesophytic 

 than is commonly the rule; but in the drainage valleys 

 and on the median plane the ordinary type roadway 

 with its varied plant societies occur. The most char- 

 acteristic roadside shrubs of the Ridges are Rhus aro- 

 matica, Rhus toxicodendron, and Celastrus scandens. 

 Other quite common species are Rhus glabra, Rubus 

 occidentalis, Rubus villosus, Rubus Canadensis, Cra- 

 taegus, Prunus, Smilax, and Vitis. 



The most characteristic herbaceous plants are As- 

 ter multiflorus Ait. (Dense-flowered Aster); Asclepias 

 tuberosa L. (Butterfly-weed, Pleurisy root); and Pen- 

 stemon hirsutus (L-) Willd. (Hairy Beard-tongue). 



In this locality, the writer has found Aster multi- 

 florus growing only on the Ridges, while at Chicago, 

 111., it occurs on level sandy commons or even along 



