1896] ROSAE AMERICANA 13 
exterior sepals sometimes bear lateral appendages. The authentic 
specimens whieh I have received from Mr, Porter have glabrous 
leaves. 
Under the name &. Arkansana, Watson has not well included 
the preceding form, which alone constitutes R. Arkansana as it 
had been described by Mr. Porter, but applies it to tall forms, 
with stems attaining six feet in height and bearing floriferous 
branchlets which arise directly from the stem or are borne on 
the branches. 
According to the abundant material which I have brought 
together in my herbarium under the name &. Arkansana, this 
species does not always have simple stems terminated by a many- 
flowered inflorescence and more or less setigerous. It may give 
rise to stems more or less tall and branching. In this case, the 
entire stem perhaps is clothed with numerous setaceous prickles 
which completely cover it or the greater part of the floriferous 
branchlets, which are then as setigerous as those of XR. acicularis. 
It remains to be seen whether X. Arkansana in the dwarf state or 
in the tall bushy state may not be sometimes completely unarmed, 
with its floriferous branchlets entirely bare of prickles as are the 
upper branches. I have reason to think so. But in the last case 
what remains to distinguish R. Arkansana from R. blanda? 
Nothing seems to remain, for when the former produces floriferous 
branchlets upon the stem of the second year, or on the branches, 
these floriferous branchlets do not have four or five pairs of leaf- 
lets as in the false floriferous branchlets of &. Arkansana as con- 
stituted by Mr. Porter, but leaves of only five or seven leaflets, as 
those of R. dblanda ; and, on the other hand, I do not see any dif- 
ference between the normal branches of the two species. Per- 
haps it can be claimed that in R. Arkansana the exterior sepals 
are a little less rarely appendaged than in X&. dlanda. 
It appears, then, that between these two roses there is a 
simple difference in the degree of abundance of prickles. The 
leaflets are the same, either glabrous or pubescent, and the floral 
organs appear to be identical. 
Despite the extremely close affinity of these two forms, I think 
