66 MANUAL OF TROPICAL AND SUBTROPICAL FRUITS 



statement that an avocado belongs to the West Indian, Guate- 

 malan, or Mexican race gives one an idea of the relative hardi- 

 ness, season of ripening, and commercial character of the fruit. 

 The botanical standing of the cultivated races, as at present 

 understood, and the characters which serve to distinguish 

 them horticulturally, are shown in the following key : 



1. Leaves anise-scented ; skin of fruit thin (rarely more than ^ 



inch in thickness) Persea drymifolia 



MEXICAN RACE of horticulture 



2. Leaves not anise-scented; skin of fruit thicker (from -fa to i 



inch in thickness) Persea americana 



a. Fruit summer and fall ripening; skin usually not 

 more than T V inch thick, leathery in texture. 

 WEST INDIAN RACE 



6. Fruit winter and spring ripening; skin tk to | inch 

 thick, woody in texture. 

 GUATEMALAN RACE 



One variety cultivated in the United States, the Fuerte, 

 appears to be a hybrid between the Mexican and Guatemalan 

 races. Others of similar origin are likely to appear at any 

 time, hence it is desirable to establish a group to include 

 hybrids. 



The avocados of the West Indian race have been developed 

 in the tropical lowlands ; the Guatemalan race, on the other 

 hand, is a product of the highlands. At intermediate eleva- 

 tions varieties appear which belong to neither of these races, 

 but possess some of the characters of each. These intermediate 

 forms cannot be classified with accuracy. 



In selecting varieties for commercial planting, it must be 

 borne in mind, first of all, that the tree must be vigorous and t 

 hardy enough to grow successfully in the particular location 

 which the planter has in view. Secondly, it must in time pro- 

 duce sufficiently large crops of marketable fruit to make its 

 culture commercially profitable. It is not necessary that it 



