THE ROOT 



41 



green coloring matter, is able like all green plants to provide for itself; 

 and it does carry on the work of forming plant food in a quite normal 



30. Roots of the Yellow Gerardia, some of 

 them parasitic on the root of a Blue- 

 berry bush. 



way even while taking the sap 

 of other plants. This is, there- 

 fore, the case of a partial para- 

 site. 



61. Parasites proper, which 

 strike their roots into the tissues 

 of living plants, or form attach- 

 ments to their surface so as to 

 suck up their juices, are amongst 

 the most interesting of all vege- 

 table forms. Of this sort is the 

 Mistletoe (Fig. 31), 1 the ^seed 

 of which germinates on the 

 bough where it falls or is left 

 by birds ; and the forming root 

 penetrates the bark and en- 

 grafts itself into the wood, to 

 which it becomes united as 

 firmly as a natural branch to 

 its parent stem ; and indeed the 

 parasite lives just as if it were 

 a branch of the tree it grows 



and feeds on. A most common parasitic herb is the Dodder (Fig. 32), 

 which abounds in low grounds in summer, and coils its long and 

 slender, leafless, yellowish stems resembling tangled threads of yarn 

 round and round the stocks of other plants; wherever they touch, 

 piercing the bark with minute and very short rootlets in the form 

 of suckers, which draw out the nourishing juices of the plants 

 laid hold of. Other parasitic plants, like the Beech Drops and Pine- 



1 Not the Mistletoe proper of the Old World. The plant represented is 

 an American relative of the well-known European planjt, very much 

 smaller, and properly denominated the Dwarf Mistletoe. 



31. Plants of the Dwarf Mistletoe para- 

 sitic on a Branch of the Spruce. 



