and one from Dr. Torrey with the lower part of the frond
missing !
Aspidium Thelypteris is sometimes found with most of the
veinlets simple, and the lower pinnæ a little contracted, so that it
is perhaps well to indicate some of the most important distinctions
in parallel columns.
A. NOVEBO RAC ENSE .
Stalk shorter than the frond.
Frond with a long and slender apex,
and much contracted at the base.
Pinnæ closely sessile.
Lobes flat.
Veinlets mostly simple.
Sori near the margin.
Spores slightly wing-margined.
A. TH E L Y P T E R IS .
Stalk often longer than the frond.
Frond short-pointed ; the base but
little contracted, if at all.
Pinnæ with a very short but evident
stalk.
Fruiting lobes oftenest slightly reflexed
over the sori.
Veinlets commonly forked.
Sori midway between mid-vein and
margin, or nearer the mid-vein.
Spores wingless.
The specimen of Polypodium Noveboracense in the I.innman
herbarium lacks the lower part of the frond, but has simple veinlets,
and is slightly pubescent; so that there is little doubt of its
being the present species.
Mr. Emerton has drawn a plant of ordinary size : the long creeping
root-stock is very characteristic. A portion of a pinna, enlarged, shows the
venation and the position of the so r i; and the Indusium, highly magnified,
shows the marginal glands and the hairs.
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