34 Agricultural Experiment Station, Ithaca, IST. Y. 



Even in wild specimens, the flat stones of P. nigra is often 

 associated with, the glandless leaf-stalks of P. Americana, and 

 vice versa; and there appears to be equal inconstancy in the 

 character of calyx lobes and sizes of flowers. In fact, the same 

 cultivated variety, when grown in different places, has been 

 referred to both species. I am obliged, therefore, for the pur- 

 poses of this paper, to unite Prunus nigra with P. Americana. 

 This I regret the more because it is undoubtedly true that there 

 are two well-marked, wild varieties — possibly species — passing 

 as P. Americana, and growing together in the east. One is a 

 twiggy, virgate grower, with large and mostly earlier flowers; the 

 other is a stout and stiff grower, with small flowers. So far as 

 I have been able to determine, the fruits and stones of these 

 two forms, save possibly in time of ripening, are not character- 

 istically distinct. These forms are certainly common in central 

 New York and in Michigan, where I have often observed them. 

 Dudley records them in Cayuga Flora.* Some of these differen.'es 

 are detailed in the following letter from Professor Charles A. 

 Davis, of Alm.a, Michigan, accompanying specimens of the trees 

 mentioned. The specimens were referred to Professor Sargent, 

 who places the first or large-flowered form with P. nigra and 

 the small-flowered form with P. Americana. " The large-flowered 

 form ia the more common and blooms about a week or even ten 

 days before the other, and usually before the leaves begin to 

 appear. The small-flowered form I have never found until this 

 spring, when I came upon a clump of it in full bloom, and 

 at once became interested in it because of its decided differences 

 from the other and common form. The trees were larger, more 

 spreading, and with a much rougher bark than the large-flowen^i 

 form; and a number of the trees bore flowers with a decidedly 

 yellowish tint, which was very noticeable from a short distance. 

 The fruit was late, maturing the middle of September, and 

 was reddish, almost purple in very ripe specimens, with a whitish 

 bloom, small and rather palatable." It is easy to place too great 

 confidence in the seasons of blooming and ripening, for these 

 characters are variable. This is well illustrated in the case of 



* The Cayuga Flora, Ithaca. N. Y. 1886, p. 27. See also Flora Clilcago. 



