PAFASITES. 151 



northern range of any of our air-plants. 

 Another interesting and still more peculiar 

 class of roots are those of parasites, plants 

 which steal their food directly from other 

 plants. Many of our common flowering 

 plants are either wholly or in part parasitic. 

 The wild gerardias and some related plants 

 attach some of their roots to the roots of 

 other plants and thus obtain a part of their 

 nutriment, but otherwise these plants are not 

 peculiar and their fair exteriors give no hint 

 of the robbery that is hidden beneath the 

 surface. Other kinds of plants, however, 

 make an open profession of their guilt, for 

 their white and 

 blanched colors 

 testify that all 

 their food is sto- 

 len ready made. Fig. 98. 

 and they need no leaf-green with which to 

 elaborate crude materials. Such plants are 

 the Indian-pipes and beech-drops. The roots 

 of parasites are usually broadened and sucker- 

 like where they attack some other root, as is 

 shown in Fig. 98. 



