Pteris trifh ylla. M a r t e n s & G a l e o t t i . Syn. Fil. Mex., p. 5 1, t . 14,
Fig. I .
Pteris trifoliata, Fée, 8me Mém., p. 114 .
H a b . — “ Shady woods, Middle and Ea.st Florida,” Dr. C h a p m .\n .
Edges of limestone sinks or chasms, near Ocala, Florida, Mr. W. H,
S h o c k l e y , Captain J. D o n n e l l S m i t h . Mexico, Guatemala, Italy, Crete,
Corsica; from the Ural Mountains to Arabia, the Himalayas and Japan;
Abyssinia, and in the Philippine, Fiji and Hawaiian Islands {Synopsis
Filicum').
D e s c r i p t i o n : — The root-stock creeps just beneath the
surface of the ground, and is several inches in length, by
nearly a quarter of an inch in thickness. It is thickly covered
by the short adherent bases of old stalks, which are found on
all sides of it. The roots are long and slender, branching, and
emitting abundant slender fibres.
The fronds borne by each root-stock are very numerous,
those produced early in the season smaller and sterile, while
those of later growth are taller, larger and more generally
fertile. The fronds of one year remain green until after those
of the succeeding year are developed. The stalks are about
half a line in diameter, and often over a foot long, sometimes
nearly two feet long. In the dried specimens they are
stramineous, and deeply furrowed on the anterior side, but
in the living plant they are greenish, and the furrow is much
shallower. They are somewhat rigid, erect, and smooth except
for a little mostly deciduous chaff near the base. This chaff
consists of delicate little amber-brown lanceolate-acuminate
t,,-: Î
4 i
scales, destitute of midnerve, the cells arranged in a somewhat
clathrate or lattice-like way, especially those of the very
slender point. The section of the stalk shows two obliquely-
placed strap-like fibro-vascular bundles.
The fronds of very young plants, and some of the earlier
fronds of mature plants, consist of only three pinnæ, all sessile
at nearly the same point. The middle pinna is twice or
three times as long as the side ones, and measures anywhere
from one to five or six inches in length, and from three to
six lines in width. Such fronds are commonly, but not always,
sterile. Pteris triphylla, of Martens & Galeotti, a name
altered to t r if0 Hat a .hy Fée, was founded on plants with such
fronds, but is not deserving of being considered even a variety
of the species. This form is found among the specimens
of all those persons who have gathered the species in Florida.
In the next degree of composition the two side pinnæ are
parted almost to the very base, rendering the frond quinate,
but with the middle pinna, as before, decidedly the longest.
From this condition the fronds pass by stages to the most
complex form observed among the Florida specimens, in
which the lowest pinnæ are three-parted, the second, third
and perhaps fourth, or even fifth, pair simple, the upper side
of the base sessile, the lower side more and more decurrent
on the midrib, and the terminal pinna distinct or nearly so,
and usually the longest of all.
In the sterile frond the pinnæ and pinnules are linear-
lanceolate, tapering from neai' the middle to both base and
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