460 PLANTS AND MAN 



whitish flowers. Burdock is a European immigrant which has 

 adapted itself as a roadside weed; the bushy plants have large 

 heart-shaped leaves and small purple disc flowers grouped in a 

 spherical head and provided with sharply barbed bracts. The 

 common thistle is well known for its spiny foliage and flower 

 heads; most of our species are introduced European plants. 

 The small flowers vary in color from white to purple. Basket 

 FLOWER, found from the Mississippi valley to Kansas and 

 Arizona, is closely related to the cultivated bachelor's button; 



A W/ B 



Fig. 280 — Members of the Thistle Family with both ray and disc flowers in the 

 flower head include asters (A) and daisies (B). 



the spherical flower head lacks spiny bracts and is made up of 

 rose colored flowers with fringed lobes. 



Asters are the most numerous and colorful of our autumn 

 wild flowers. Some fifty species are found in the northeastern, 

 and over a hundred in the southern, states; the number of species 

 decreases as one goes westward. Asters have heads made up of an 

 outer series of blue, pink or white ray flowers, and a central mass 

 of golden yellow fertile disc flowers. One of the most beautiful 

 eastern species is the New England aster found in rich fields from 

 New England to Kansas, whose flower heads often reach a 

 diameter of an inch or more, each fringed with forty to fifty 



