1898] BRIEFER ARTICLES 49 
varieties cannot be classified without a knowledge of the botanical 
species ; and these species cannot be fully understood without a wide 
study of the cultivated varieties. This is my excuse for calling atten- 
tion here to some of the species, supposedly among the best known in 
American botany. 
Prunus AMERICANA Marshall.—In the absence of Marshall’s type 
specimens his original description makes it impossible to say whether 
he had in hand the western form which now passes generally under 
this name, or the northeastern Prunus Americana nigra. As long as 
the two are consolidated after the manner of Gray’s Manua/ it makes 
little difference. If, however, the group is to be divided into two 
species, according to Sargent’s Sy/va and Britton and Brown’s ///us- 
trated Flora, it is an open question which part should bear Marshall’s 
name. 
PrRuNUS AMERICANA NIGRA F, A. Waugh.—This question as to 
whether our common American plums should constitute one species 
or two has not yet been fully settled. On the one hand we have Sar- 
gent, Britton and Brown, Sudworth' and others leaning strongly 
toward thé separation of the two groups; while the Gray publications 
and the numerous followers of Gray, including Bailey, one of our 
foremost plum students, hold out for consolidation. It seems to me 
that, were I unacquainted with the cultivated varieties, I would not 
hesitate to recognize two species ; but the many surprising combina- 
tions of Americana and nigra characters seen in the garden, and the 
impossibility of disentangling all these varieties, make it more con- 
venient to regard Aiton’s group as a botanical variety of Prunus 
Americana. 1 set forth more fully my reasons for taking this view at 
the time when I proposed to call this group P. Americana nigra.” 
PRUNUs AMERICANA MOLLIS Torrey & Gray.— Sudworth?® proposes 
the name Prunus Americana lanata for this variety. No explanation 
is given for this change, and the variety name of Torrey and Gray 
seems likely to stand. This variety marks the southwestern evolution 
of the great Americana group, as P. Americana nigra is a northeastern 
modification. The extreme forms are quite as distinct, and by them- 
* Nomenclature of the arborescent flora of the U.S. Bull. 14, U. S. Dept. Agr., 
Diy, Forestry, 
“Bull. Vt. Exp. Sta. 53:60. 1896. 
3 Op. cit, 237. 1897. 
