36 



BEGINNERS* BOTANY 



Some plants bear aerial roots, that may propagate tJio 

 plant ox may act as draws. They are often called prop-roots. 

 The roots of Indian corn are familiar (Fig. 38). Many 

 ficus trees, as the banyan of India, send out roots from 

 their branches ; when these roots reach the ground they 

 take hold and become great trunks, thus spreading the 



top of the parent tree over large 

 i) I^\ I' H areas. Tlie mangrove tree of the 



vr %Ui^ tropics grows along seashores and 



sends down roots from the over- 

 hanging liranches (and from the 

 fruits) into the shallow water, and 

 thereby gradually marches into the 

 sea. The tangled mass behind catch- 

 es the drift, and soil is formed. 



Adventitious Roots. — Sometimes 

 roots grow from the stem or other 

 unusual places as the result of some 

 accident to the plant, being located 

 without' known method or law. They 

 are called adventitious (chance) 

 roots. Cuttirfes of the stems of 



Fig. 38. — Indian Corn, 

 showing the brace roots 

 at 00. 



roses, figs, geraniums, and other 

 plants, when planted, send out ad- 

 ventitious roots and form new 

 plants. The ordinary roots, or soil roots, are of course not 

 classed as adventitious roots. The adventitious roots arise 

 on occasion, and not as a normal or regular course in the 

 growth of the plant. 



No two roots are alike; that is, they vary among them- 

 selves as stems and leaves do. Each kind of plant has its 



