Volume I I Number 



The Plant World 



NOVEMBER, 1908 



THE COURSE OF THE VEGETATIVE SEASONS 



IN SOUTHERN ARIZONA. 



(Continued) 



By. D. T. MacDougal. 



Of the agave, "Spanish bayonet" or "century plants" 

 this region has but few representatives. The slopes and 

 mountain sides between 3000 and 4000 feet bear the rosettes 

 of Agave pahneri, which after a period of development vary- 

 ing from a few to many years, sends up a central flower stalk in 

 the foresummer with extraordinary rapidity, growing in length 

 as much as a foot per day and quickly forming flowers and 

 seeds. This effort exhausts the resources and terminates the 

 life of the individual, and the entire cycle of these "century 

 plants" is directed to this one effort of arriving at mature 

 size with an accumulated food supply that will enable them 

 to perfect a crop of fruits and seeds. This habit makes the 

 agaves an important source of food for the southwestern 

 Indians, who take the rosettes when nearly mature and after 

 cutting away the tips of the leaves, bake the central stem and 

 attached leaf-bases for the sugary substances to be obtained, 

 making what is known as mescal. The mescal pits used a 

 decade ago are numerous in the foothills of the mountains 

 in this region, and even yet one may occasionally surprise an 

 Indian feasting upon this prized delicacy. 



Growing with Palmer's agave and extending much 

 farther up the mountain sides are great fields of Agave 

 sc/iottii, the narrow leaves being no wider than the finger 



