196 THE EVOLUTION OF OUR NATIVE FRUITS 



They are usually covered with a thin bloom, and are 

 more or less marked by small spots. They are variable 

 in period of ripening, there being a difference of no 

 less than two months between the seasons of some 

 of the cultivated varieties. In color they range from 

 the most vivid crimson to pure golden yellow. 



In the seven years which have now elapsed since 

 I made my first serious study of the botanical fea- 

 tures of these fruits, I have had trees and botanical 

 specimens of the native plums constantly before me 

 in great variety, and certain novel conclusions 

 respecting the botanical status of this hortulana 

 class have been forced upon me. If one attempts 

 to make an analytical study of this Prunus hortu- 

 lana, he is first of all impressed with the singular 

 fact that, whereas cultivated varieties of it are numer- 

 ous, it is rare in a wild state, and is almost 

 unknown to field botanists. It turns up now and 

 then in the Mississippi valley region and in Texas, 

 but the stations of the feral plants are widely scat- 

 tered and local. Associated with this comparative 

 rarity of the wild plant is the fact that the species 

 has no distinctive range. It grows where both the 

 Chickasaw and Americana types grow, but it appears 

 not to occur where either of those species alone 

 grows. Well-marked species of plants nearly 

 always have an individual geographical range, but 

 the distribution of Prunus hortulana seems to be 

 accidental. The next remarkable feature which strikes 

 the critical student is that, although there are cer- 

 tain types of it which seem to have well-marked 

 specific characters, it grades off imperceptibly to the 

 Chickasaw group on one hand and to the Americana 



