CHAPTER XIV 



DEPENDENT PLANTS 



Thus far wc have spoken of plants that liave roots and 

 foliage and that depend on themselves. They collect the 

 raw materials and make them over into assimilable food. 

 They are independent. Plants without green foliage can- 

 not make food ; they 

 must have it made for 

 them or they die. 

 They are dependent. A 

 sprout from a potato 

 tuber in a dark cellar 

 cannot collect and elab- 

 orate carbon dioxide. It 

 lives on the food stored 

 in the tuber. 



All plajits with natu- 

 rally white or blanched 

 parts are dependent. Their leaves do not develop. They 

 live on organic matter — that which has been made by a 

 plant or elaborated by an animal. The dodder, Indian 

 pipe, beech drop, coral root among flower-bearing plants, 

 also mushrooms and other fungi (Figs. 131, 132) are exam- 

 ples. The dodder is common in swales, being conspicuous 

 late in the season from its thread-Uke yellow or orange 

 stems spreading over the herbage of other plants. One 

 kind attacks alfalfa and is a bad pest. The seeds germin- 

 ate in the spring, but as soon as the twining* stem a:- 



106 



Fig. 131. — A Mushroom, example of a sapro- 

 phytic plant. This is the edible cultivated 

 mushroom. 



