74 



PEACTICAL BOTANY 



part of the plant body, with its terminal bud or sometimes 

 lateral buds, is comparatively safe from extremes of cold or 



dryness, and serves 

 to carry the life of 

 the plant over from 

 one growing season 

 to another. 



66. Water storage 

 in stems. All living 

 stems of plants con- 

 tain water, and in 

 the case of plants ex- 

 posed to long peri- 

 ods of drought the 

 water stored in the 

 stem may be abso- 

 lutely necessary to 

 tide over the rainless 

 months. Some cacti 

 and other succulent 

 desert plants con- 

 tain enough water 

 to make it possible 

 for men and other 

 animals to drink 

 from them when they 

 are cut open. The 

 amount of water 

 stored in some desert 

 plants is sufficient to 

 carry on growth and 

 reproduction for ten 

 years or more with- 

 out renewal from 

 outside sources. The trunks of certain South American trees 

 are so swollen as to constitute something like aerial tubers, 



FIG. 61. Lengthwise section through a young 

 hyacinth plant 



st, the cushion-shaped stem at the hase of the bulb ; 



6, the young bulb from which the next year's growth 



would proceed; sc, bulb scales; f.s, flower stalk. 



Reduced 



