■ : i l
AUosortis mucronatus, E a ton , in SllHman’s Journal, July, 1856, p: 138.—
T o r r e y , Pacif. R. Rep., iv., p. 160.
Pdlcta tmccronata, E a ton , in Bot. Mex. Boundary, p. 233, in part, not
of Fée.
H a b . — California, common on dry exposed rocks from Mendocino
County to San Diego. Also on Guadalupe Island, P a lm e r . Professor
B r ew e r notes ; “ This species is abundant on the very dry mountains
in the western part of the S ta te ;— grows often in tufts in the rocks,
where it receives no moisture whatever for several months in the summer,
and is exposed to an intensely scorching sun.”
D e s c r i p t i o n :—The root-stock of this fern probably attains
a length of three or four inches: it is more or less
branched, the branches often being short and nodose, giving
the root-stock a somewhat knotted appearance. It has a
dense covering of narrow cinnamon-brown scales, some with
a strong blackish midnerve, and others on the same root-stock
without midnerve, but all more or less denticulate along the
edges, especially towards the tips.
The stalks are clustered on the knots of the root-stock,
and near its end, and rise to a height of from two or three
inches to nearly a foot. They are singularly rigid and wiry,
as are the general and partial rachises. In the largest examples
they are fully the tenth of an inch in diameter. Their
color varies from nearly black to purplish-brown or dark-
cinnamon-brown. Except at the very base they are devoid
of chaff. One specimen from Long Valley, Mendocino County,
has on the upper part several short and thorn-like, but blunt
protuberances; reminding one of the aculeate stalk occasionally
seen in tropical ferns. The section shows a very
thick exterior woody sheath, and in the middle a single fibro-
vascular bundle, which is roundish-triangular, and has slinht
furrows along the three sides, the deepest one along the
side next tlie anterior side of the stalk, which is slightly
flattened.
The fronds are usually about half as long again as the
stalks, and are broadly ovate-lanceolate or deltoid-lanceolate
in outline. The fronds of mature plants are regularly tripinnate.
The primary pinnæ are elongated, and commonly form
an angle of about sixty degrees with the rachis, though
sometimes they spread horizontally, and at others they rise
very obliquely. The lowest pair of secondary pinnæ arc
placed very close to the main rachis. The secondary pinnæ
vary from hve to sixteen pairs, normally they are trifoliolate
and resemble the three toes of a bird's foot, whence the very
appropriate name given to this species by Sir W. J. Hooker.
But m very small specimens, such as those on which my
AUosorus mucronatus was founded, the secondary pinnæ are
often simple, and then the plant approaches P. Wrightiana
with inconvenient proximity. In very large plants, like those
collected by Dr. Kellogg in Mendocino County, some of
the secondary pmnæ are more or less elongated, and become
pinnately five-to-seven-foliolate. The ultimate pinnules, in all
the native specimens which I have seen, are less than three
lines long, and have the edges rolled in revolutely almost or