46 AMERICAN FERN JOURNAL 
region in general, due either to locally more complete de- 
composition of the vegetable matter, or to the presence 
of more or less calcareous lenses in the underlying sand 
formation. These facts, together with its occurrence 
on limestone rocks, lead to its classification as a calcar- 
eous soil plant tolerant of acidity to a considerable but 
not an extreme degree. 
Asplenium resiliens (parvulum) has been recorded 
more often on limestone than on other rocks, and sev- 
eral observations upon it, in southern Virginia, confirm 
the correctness of its usual classification as a calcareous 
soil plant practically intolerant of acid conditions. It 
is usually rooted in limestone fragments of alkaline re- 
action, and even in occurrences in mossy humus the 
acidity was not observed to exceed low minimacid values. 
The more widespread Asplenium Trichomanes, observed 
throughout the region studied, is well known to occur 
on all sorts of rocks. On limestone it often grows in the. 
open, in soil composed of rock fragments and accord- 
ingly alkaline in reaction. On sandstone, schist, gneiss, 
etc., it usually grows, however, in soils made up of de- 
composed vegetable matter accumulated in places more: 
or less sheltered from the action of the rain, so that little 
lime can be leached out, and the reaction is circumneu- 
tral or rarely subacid. It is thus to be considered a cal- 
careous soil plant moderately tolerant of acidity. 
The writer has been unable to study Asplenium viride 
in the field, as his visit to the region of Willoughby Lake, 
Vermont, was too brief to permit a climb to its recorded 
place of growth near the top of the cliffs of Mt. Hor. 
The rock of this mountain is, however, a calcareous 
gneiss (of Ordovician age), so the fern would be sus- 
pected of calcareous soil tendencies. Tests of soils of 
specimens in the National Herbarium, from the locality 
at Smuggler’s Notch, showed in fact neutral to very ~ 
slightly acid reactions, confirming the correctness of this 
inference. 
