THE DRUPE-FRUITS 153 



north as central New York. The leading varieties under cultiva- 

 tion are Arkansas, Pottawattamie, Robinson, Newman, Wild 

 Goose, and Downing. 



Cherries 



All of the commonly cultivated cherries, now several hundred, 

 although possibly 1500 have been described, belong to two 

 species or are hybrids between the two. Four other species are 

 of interest to pomologists for cultivated varieties of minor im- 

 portance or for use as stocks. Botanists enumerate more than a 

 hundred wild cherries, some of which may prove of value when 

 domesticated or for hybridization. The two species of prime im- 

 portance to pomologists are P. CerasiiSy the sour cherry, and 

 P. avium, the sweet cherry. 



KEY TO CULTIVATED SPECIES OF CHEREIES 

 A. Plants trees. 



B. Flowers in few-flowered branching clusters; leaves 

 much longer than broad. 



C. Leaves small, short, ovate or obovate, firm, short- 

 pointed 1. P. Cerasus. 



CC. Leaves large, long, oblong-ovate, soft, taper- 

 pointed 2. P. avium. 



BB. Flowers in many-flowered umbel-like clusters; 

 leaves small, very broad, nearly round, firm, shining, 

 perfumed 3. P. Mahaleh. 



AA. Plants very dwarf and bush-like. 



B. Under surface of leaves tomentose 4. P. tomentosa. 



BB. Under surface of leaves glabrous or nearly so. 



C. Leaves less than 2 inches long, narrowly oblanceo- 

 late, thin; petiole glandless 5, P. pumila. 



CC. Leaves more than 2 inches long, broadly ob- 

 lanceolate, thick; petiole usually with 1 or 2 small 

 globose glands 6. P. Besseyi. 



Sour cherries. 



Because the trees are hardy, relatively free from disease, easy 

 to care for, and very productive, the sour cherry is grown and 

 esteemed in temperate climates the world over. In all northern 

 fruit regions in North America it is a favorite for home and 



