TUBERS AND BULBS 



33 



Beet, radish parsnip, turnip, salsify, carrot, dahlia roots, 

 are examples. These tubers are usually much longer than 

 broad, and generally taper down- 

 wards. (Fig. 47.) A good example of 

 stem-tuber is the kohlrabi. (Fig. 48). 



-tuber above ground. 

 Kohlrabi. 



49. A multiplier oni< 



80. A much thickened part composed of scales or plates 

 is a bulb. The bulb may be scaly, as in the lily; or it may be 

 tunicated, — made up of plates or layers within layers, as 

 the onion. 



81. Small bulbs borne amongst the foliage or flowers 

 are known as bulblets. 

 Such are the "top onions," 

 and the little bulbs that 

 the tiger lily (Fig. 31) 

 bears on its stem. Bulbs 

 that grow around the main 

 bulb or which are formed 

 by the breaking apart of 

 the main bulb, are known 

 as bulbels. Many bulbous 

 plants propagate by means 50 . section of 



G 



ultiplier onion. Natural size. 



