The Nigra Group 57 



been revived by such botanists as Sargent, Britton 

 and Sudworth. 



The present writer, as elsewhere explained, has 

 taken a compromise view. The Nigra group seems 

 to me to be fairly distinct and manageable pomologi- 

 cally, to be different enough from Priinns amcricana 

 to deserve separate botanical mention, but still to be 

 so closely related to the latter species as to be best 

 understood when called a variety of it. 



Whatever the standing of the group botanically, 

 it will be convenient to keep it as a separate pomologi- 

 cal group, in spite of the fact that many of the varie- 

 ties are very difficult to assign with certainty either to 

 the Nigra or the Americana group. This was first dis- 

 cussed as a separate group by the writer in 1897.* 

 The characters which may be relied on to distinguish 

 varieties of this section in most cases are: Dark-col- 

 ored bark; glandular serrate calyx lobes; broad leaves 

 with glandular petioles; flowers larger than in the 

 Americana group, often pinkish, and especially show- 

 ing pink when half opened, the calyx lobes being also 

 pink; fruit usually darker colored than in the Amer- 

 icana group. 



In their habits and in most of their pomological 

 characteristics, these varieties are much like those of 

 the Americana group. They are exceedingly hardy, 

 being probably the hardiest fruit plant known on this 

 continent. Still, the Americanas are hardy enough 

 for any section where any sort of farming can be 

 carried on. 



♦Vermont Experiment Station Report, 10:102. 1897. 



