7 4 FERNS OF NORTH AMERICA.
The fronds are similarly short-stemmed ; they are similarly lanceolate
in outline, with an acuminate apex and a gradually narrowed
base ; the texture is much the same ; the pinnæ and lobes very
like those of the other species ; and even in the disposition of
the veinlets, and the character of the indusium, there is but
very little difference. But while Aspidium Noveboracense has a
long and slender cord-like rhizoma, which creeps far in advance
of the position of the fronds, the present species has a short and
somewhat stouter rhizoma, covered by the imbricated or overlapping
bases of former stems; and the fronds, several in number,
are produced apparently from the advancing end of the rhizoma,
and stand together in a crown, or circle, just as in the common
A . spimdosum and its allies. A comparison of Mr. Emerton’s
drawings in Plates V I I . and X. will show both the great resemblance
of the two ferns, and their essential distinction. The lobes
of the pinnæ in A . Nevadense are a little more apt to be crenated,
or even slightly toothed, than those of the other species. . The
pubescence on the under side of the veins is scantier in this
species, and the lobes are not at all ciliated. Another constant
character seems to be, that the under surface of the frond is copiously
dotted with minute shining resinous globules. The lower
part of the stalk bears a few chaffy scales, and similar scales are
found on the root-stock.
Mrs. Austin, to whom I am indebted for a full series of fine
specimens of the ferns of Plumas County, California, has noticed
in this fern a sort of sleeping and waking. She says, “ The new
Aspidium Nevadense has one peculiarity about the fruiting fronds
FERNS OF NORTH AMERICA. 75
which I have noticed in no other fern ; that is, the divisions of
the pinnæ are closed or folded together early in the day. I
noticed this last fall. When I went early (while it was yet cool) in
the morning for specimens for the press, I would not gather them,
as I did not think they would make nice specimens, but went
farther up the creek, collecting other plants, and did not return
till two or three o’clock, when I found the pinnæ all open, and the
fronds fit to press.” Some later observations confirmed her in
the opinion that this fern at least has its daily periods of contraction
and expansion ; but whether the change is caused by alternations
of light and darkness, dampness and dryness, or heat and
cold, is yet undetermined.
This fern is more or less closely related to that group of
Tropical-American species which clusters about Aspidium con-
terminum; but that species has an erect, not a creeping, rhizoma,
and a heavier and more rigid frond. But our plant clearly
belongs to the same section of the genus, and would, accordingly,
be a Nephrodium, § Lastrea, of Baker, though, as well as can be
seen from the withered indusium, scarcely an Odchlamys of Fée.
The same name, Aspidium Nevadense, was given by Bois-
sier to a Spanish fern; but, as that has proved to be only an
already well-known species, there is no impropriety in conferring
the name on a fern from the Sierra Nevada of our own country.
Plate X. — Aspidium Nevadense. An entire plant, reduced to about
one-third or one-fourth of the natural size, and colored, occupies the middle
of the plate. Two fronds, and their root-stock, of natural size, are drawn
in outline. A t the left is a single segment in fruit, magnified about ten
diameters ; and at the right an indusium, highly magnified.
Ü. ri • i l ]
k i
J
M i
V '
b d ‘ :
'•il
, {■
id-*
' i \
; i (
■1 M '■
, *■ P i r -
' L 1 ' .
i . ' '-r-t'
l i r j
jU a i