Do only large plants flower? 7, 

living under conditions where extremes of dryness are not as pro- 
nounced. As certain areas became hotter and dryer these plants 
changed their forms and the leaves were modified into thickened 
bodies hardly recognizable as leaves. Many plants gave up their 
leaves altogether and the leaf functions were transferred to swollen 
stems and were replaced by defensive spines or other protective 
covering. By reducing the leaf surface, the moisture usually given 
off was reduced to a minimum. The plant bodies became covered 
with a waxy coating, hairs, and other specialized evaporation resisting 
coverings for the conservation of moisture until the next rains, which 
were readily absorbed and retained through the dry seasons. 
Succulents are found in many plant families growing in all parts 
of the world, from high barren mountain slopes to arid wastes. 
Whereas most of the other succulents are found in Africa—though 
also in many other countries—most cacti are native of the Americas. 
Cacti range in size from the Giants of Arizona weighing tons to 
the Button Cactus the size of a penny. The other succulents, too, 

LEFT: One of the smaller cacti—Rebutia minuscula. RiGHT: Of the other 
succulents, the evening flowering Stomatium fulleri is thumb-size. 
