1918] Fernald,— Rosa blanda and its Allies 91 
In the genus Rosa this segregation along lithological lines is as 
pronounced as in other genera, with the result that in the acid or 
hardly calcareous coastwise region from southern New England to 
northeastern New Brunswick, the Magdalen Islands and southern 
Newfoundland Rosa virginiana L. and R. carolina L! (R. humilis 
Marsh.) abound in the drier habitats and R. nitida Willd. in the bogs; 
while swamps and pond-shores northward to Megantic Co., Quebec, 
north-central Maine, and southwestern New Brunswick are often 
characterized by the abundance of R. palustris Marsh. (R. carolina 
Auth., see foot-note 1). In these four species of southern arid habi- 
tats the infrastipular prickles are normally present, the pedicels, 
hypanthiums and hips more or less bristly, and the achenes are borne 
at the base of the hip. 
In the calcareous area to the north and northwest, however, from 
the St. John valley in Maine to Gaspé and Anticosti, these species 
are practically unknown (with the exception of rare colonies of R. 
nitida in sphagnous bogs and local colonies of R. virginiana in the 
Devonian sandstones about Gaspé Bay) and their places are taken 
by three species of quite different character; without infrastipular 
prickles, with glabrous pedicels, hypanthiums and hips, and with the 
achenes borne on the inner walls as well as at the base of the hips. 
These three northern calcicolous shrubs have all passed as R. blanda 
Ait., and since there is some question as to the exact identity of R. 
blanda it is necessary first to consider the original description of that 
species. 
Rosa blanda Ait. Hort. Kew. ii. 202 (1789) was based upon two 
entirely different plants, which were very soon recognized by other 
botanists as belonging to quite distinct species. Aiton’s treatment 
was as follows: 
1 Rosa carolina L. Sp. Pl. i. 492 (1753) was based solely on Rosa Carolina fragrans, foliis 
mediotenus serratis of Dillenius, Hort. Elth. 325, t. 245, fig. 316 (1732). The figure of Dillenius 
is beautifully definite and there can be no question that it clearly depicts the common 1-flowered 
glabrous-leaved R. humilis Marsh. with slender straight needle-like infrastipular prickles. Not 
merely the plate demonstrates this, but the description of the shrub as not exceeding a foot in 
height and having glabrous leaves is equally definite. The taller swamp species with strongly 
curved prickles, more corymbed flowers and usually pubescent finer-toothed leaves which has 
generally passed as R. carolina was taken up by Linnaeus as R. carolina in the 2d edition of the 
Species Plantarum (1762-63), and the significance of the name thus changed. This accounts 
for the subsequent very general treatment of the Swamp Rose as R. carolina. Dr. Rydberg 
informs me that the correct name of the Swamp Rose (R. carolina of Authors) is R. palustris 
Marsh. Arb. Am. 135 (1785). Marshall's description is characteristically vague but it appar- 
ently was intended to cover the R. carolina of Authors and the name R. palustris is certainly 
appropriate. 
