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wing-like border. The lobes of the pinnæ are placed close
together, and are oblong, rounded at the apex, and set obliquely
on the secondary midribs. They are either entire or
crenately-toothed. The veins are pinnately arranged, the lower
ones forked, the upper ones simple.
The sori are seated in the veinlets a short distance below
the acute apices, and consequently near the margin of the
segments. They are rather small, roundish or slightly oblong,
and are usually seen on all the pinnæ of a fertile frond. The
sporangia have about fourteen articulations. In many sporangia
one or two slender-pointed hairs are borne near the
top, reminding one of the similar hairs of the scales of the
young stalk. The spores are ovoid, univittate, smooth and
yellowish.
This fern is taken as the type of the genus Phegopteris,
which, as explained on page 151 of this volume, is abundantly
distinct from Polypodium, though, perhaps, not sufficiently so
from Aspidium.
From P. hexagonoptera this species is distinguished by
its usually smaller size, narrower outline, and the more nearly
entire segments of the pinna. But, as in many other analogous
cases of relationship, it is sometimes difficult to decide
to which of the two species a specimen ought to be referred.
Plate LXX V, Fig. 1-4. — Phegopteris polypodioides. Fig. 2 is a segment,
enlarged about eight diameters. Fig. 3 is a sorus. Fig. 4, a spore.
P l .ate LXX V. — F ig. 5-8.
A SP ID IUM JU G L A N D IFO L IU M . K u n z e .
Walnut-leaved Shield-Fern.
A s p i d i u m j u g l a n d i f o l i u m ; — Root-stock short, erect, very
chaffy with large ovate dark-brown scales ; stalks a few inches
to a foot long, very chaffy when young; fronds four to twelve
inches long (much larger in tropical America), coriaceous,
smooth and shining above, sparingly chaffy beneath, pinnate,
or the earliest ones simple ; pinnæ short-stalked, ovate-oblong
or broadly lanceolate, the terminal ones distinct and often the
largest, the lateral ones one to eight or ten on each side, two
to six inches long, one or two inches broad, obtusely cuneate
or truncate or sub-cordate, serrate with rather distant incurved
teeth, acute at the apex; veins pinnately branched, veinlets
few in each group, nearly parallel, either free or uniting
towards the margin ; sori rather large, scattered in two or more
irregular rows between the midrib and the margin; indusium
orbicular, peltate, somewhat toothed around the edge.
Aspidmm jitglandifolium, K unze, in Linnæa, xx., p. 365. — M ettenius,
Fil. Hort. Lips., p. 87, t. xxii., fig. 6 -7^ ; Aspidium, p. 3 5 .—
H ooker, Sp. P'il, iv., p. 3 8 .— H ooker & Baker, Syn. F il,
p. 257. — E aton, Ferns of the .South-West, p. 336.
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