KOOTS 



II 



branches of seed roots, but from stems or leaves, are called 

 adventitious roots. Hence the fibrous root system of wheat, 

 and of all the other cereals and grasses, is in reality composed 

 of roots that develop adventitiously. Adventitious root 



/jt foliage 



Fig. 2. — Three germinating stages in wheat. 



systems may appear under a variety of conditions. When 

 young onion "sets" are placed in the ground, a set of roots 

 (adventitious roots) appears at their bases. If young one- 

 year-old twigs or stems (cuttings) of apple, raspberry, willow, 

 geranium, carnation, chrysanthemum, rose, or of many other 

 economic plants are placed in damp soil or sand, adventi- 



