328 PROCEEDINGS OF THE AMERICAN ACADEMY. 
discovered. It is evidently related to S. regia, Sims, and S. laciniata, 
Cav., but differs from the former very much in the form of its leaves, 
from the latter in its entire petals, and from both in the entire absence 
of glandular pubescence. From S. Virginiea, L., it differs in petals, 
pubescence, and texture of the leaves. 
SILENE LAcINIATA, Cav. Prof. W. R. Dudley calls my attention 
to the fact that the seeds in this species and its broad-leaved variety 
(S. Greggii) are not infrequently vesicularly crested, as in the Califor- 
nian S. Partshir, 
ARENARIA GRENLANDICA, Spreng. This attractive species, pos- 
sessing a wide and interesting north and south distribution, seems 
worthy of special study. The typical form, with subglobose obtusely 
pointed capsules and with stems few and decumbent from a spreading 
rosette of somewhat fleshy leaves, occurs chiefly in Greenland and 
Labrador. The common form of the mountains of Maine, New Hamp- 
shire, and Eastern New York becomes rather densely matted, and has 
many erect stems with very numerous erect less fleshy leaves about 
the base. Its capsules are ovoid to oblong and more or less acutely 
pointed. Although in temperate latitudes usually confined to rocky 
soil of the mountains or higher hills, this species descends nearly oF 
quite to the seashore in Maine, at Bath and at Mt. Desert. . It 
has also been found at Middletown, Conn. When growing at these 
lower altitudes, the plant is scarcely at all matted and the segregated 
few-stemmed individuals have simple or at least less fibrous roots and 
fewer thicker leaves than in the mountain form, with which however 
they are connected by frequent intergradations. In these forms also 
the capsule is ovoid or oblong rather than globose. Until recently the 
Shawangunk Mountains of New York have passed as the southern saris 
of this species, but there can be no doubt (see Mem. Torr. Club, 1 
14) that many of the specimens from the higher Mountains of North 
Carolina, hitherto referred to A. glabra, Michx., are practically identical 
with the plant of the White Mountains, notwithstanding the fact that the 
flowers average smaller. The question whether it is best to retain these 
forms of temperate regions in the same species with those of Greenland 
and Labrador presents much difficulty. The differences in habit, s!2° 
of the flowers, and notching of the petals are often striking. Unfortu 
nately, however, no one of these characters holds satisfactorily 1 
large series of specimens, and it appears that the change from the few- 
stemmed decumbent plant with a basal rosette of leaves and single © 
simple root to the matted plant with fibrous roots and many stems, erect — 
by mutual crowding, is a difference which may well be due exclusivelY — 
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