ROOT SYSTEMS OF MIXED-PRAIRIE SPECIES. 



47 



secondary rootlets. These are very fine and range in length from a few 

 millimeters to more than 3 centimeters. Practically all of the larger branches 

 originate within the first 6 to 8 inches of soil. No roots were found at a depth 

 greater than 3.2 feet. The whole root system is light tan in color. This 

 species, then, has a widely spreading but not deeply seated root system. 



Liatris squarrosa. — The blazing-stars are herbs which form extensive 

 autumnal societies throughout the grassland formation. This species blos- 

 soms somewhat earlier than the others and from July to September its bright 

 purple flowers are a conspicuous feature of the landscape. A number of 

 plants were examined on a sandy hillside. They were 1 to 1.2 feet in height 

 and in full bloom. This species, unlike Liatris punctata with its strong, deep 

 tap-root (Weaver, 1919:9), is provided with a large number of rather fibrous 

 roots originating from a corm, thus resembling Liatris scariosa. The corm 

 varies in depth from 3 to 8 inches. It ranges in diameter from 0.7 to 1 inch 



Fig. 17. — Corm and root system of Liatris squarrosa. 



and is from 1 to 1.3 inches long. From the base of the corm arise great 

 clusters of whitish roots, 36 to 80 of which were counted on different plants. 

 The largest are about a millimeter in diameter. All of the roots are extremely 

 fragile and hence traced with great difficulty. They spread out in the sandy 

 soil in such a manner as to form roughly a half sphere (fig. 17). Some of them 

 run parallel with the soil surface for a distance of 2 feet. Others penetrate 

 vertically downward to a depth of 2.8 feet. Within a radius of 4 to 6 inches from 

 the corm there are practically no branches. Otherwise the roots are fairly 



