Some Common Thistles. 



[march, 



believe that the seed of the creeping thistle is incapable of 

 germination. This is, however, a mistake. A certain amount 

 of seed is produced in both types of flower-heads, but chiefly in 

 those in which pollen is absent. The seeds germinate readily 

 enough either in the year in which they are prcduced or in the 

 following spring. The seedlings have two fleshy cotyledons, 

 followed soon by the ordinary leaves, which do not grow in 

 rosette form as in the other kinds of thistle. A thin tap-root 



Fig. 5. — Root of Young Spear Thistle (first year). 



descends vertically in the ground, and in very few weeks — long 

 before the cotyledons decay — adventitious buds are produced 

 upon it (Fig. 8), and also upon the lateral secondary roots in 

 great abundance. The root-system develops in all directions 

 very extensively in young and old plants, and upon all parts of 

 it buds arise which ultimately come above ground and grow into 

 strong, leafy stems. Although the creeping underground parts, 

 from which the thistle gets its common name, look very much 

 like rhizomes, they are true roots, which bear buds ; no rhizomes 



