THE PLUMS OF NEW YORK. 71 



New Foundland westward to the Strait of Mackinac and thence southward 

 to Lansing, Michigan. Its southern boundary can be but illy defined, 

 but the species is common in New England, northern New York, where 

 it is sometimes cultivated about houses, and westward at least as far as 

 the eastern shore of Lake Michigan for the species, while the western 

 form reaches the western boundary of Minnesota at least. Small ' reports 

 it as far south in the Appalachian System as northern Georgia. In the 

 great region outlined above it is distributed in more or less scattered 

 localities, being found usually in the valleys of rivers and streams, though 

 often on high lands and in open woods, in the last locations preferring a 

 limestone formation. 



There has been much discussion as to whether Prunus nigra should 

 be given specific rank or be united with Prunus americana, either as a part 

 of that species or as a botanical variety of it. Until the revival by Sargent 

 in 1892 of the name given the group by Alton in 1789, the botanists of the 

 latter half of the Nineteenth Century had for most part described the two 

 groups under Prunus americana. Since Sargent's re -establishment of 

 the species, botanists have very generally regarded it as worthy of the 

 rank. Bailey and Waugh, the leading horticultural authorities on plums, 

 however, consider Nigra as but a botanical variety of Americana. The 

 taxonomic characters of Prunus nigra seem to the writers of The Phinis 

 of New York to be as distinct as those of several other of the native species 

 of Prunus, and since the species now is generally recognized by botanists, 

 we have considered it in this work as distinct from Prunus americana. 



The two species may usually be distinguished by the following 

 differences: (i) The general aspect of the trees is very different. The 

 tree of Americana is larger, the top is more spreading, and its branches 

 longer, with more twigs, more slender and more pendulous. The bark 

 on the tnink is lighter-colored and much more shaggy than in Nigra. (2) The 

 wood of Nigra is tougher and the trees do not break as readily as those of 

 Americana. The wood is also lighter in color. (3) The leaves of Nigra 

 are larger, broader and the serrations are not so deeply incised nor so often 

 double. Very distinct and very constant are the glands to be found on 

 the teeth of the serrations on the yovmg leaves of Nigra. These glands 

 disappear as the leaves grow older, leaving a calloused point which makes 

 the serrations of Nigra rounded, while those of Americana are acute, this 



Torrey Bot. Club Bui. 21:301. 1894. 



