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116 FERNS OF NORTH AMERICA.
Phlebodium aureuni, R. B rown. — J. S m ith , “ in Hook. Journ. Bot., iv.,
p. 58.” — H o o k e r , Gen. Fil., t. 112 . — M o o r e , Ind. Fil., p. Ixxiii.
H a b . — Fpipkytic on trees, especially on the palmetto, in the peninsula
of Florida. Common in the West Indies, and in South America as far
as Brazil.
D e s c r i p t io n . — The root-stock is creeping, and properly but
little thicker than a goose-quill ; but it is so abundantly covered
with bright-brown acuminate ciliated chaff, that the apparent
diameter is half an inch. As in all the true Polypodia, the
root-stock bears scattered prominences, or knobs, to which the
separate stalks of the fronds are articulated, and from which they
fall away when finally withered.’- The height of the fronds in
the Florida plant is from a few inches to two feet, of which about
one-third is stalk, and two-thirds frond proper. The stalk is
rather rigid, perfectly smooth, when fresh somewhat glaucous, but
in herbarium specimens of a brownish color. It passes gradually
into a strong midrib.
In very young plants the frond is simple, or three-lobed ; but
’ T h is m o d e of g row th , Mr, Jo h n Sm ith , th e fo rm e r c u r a to r of th e R o y a l
B o tan ic a l G a rd e n s a t Kew, now a m an of v e n e ra b le ag e , h a s d e s c rib ed , a n d c a re fu
lly d is tin g u ish e d from th e com m o n e r mode wh ich is se e n in Asp id ium , Asp le nium,
Phegopteris, &c. T h e fo rm e r h e c a lls “ E rcm o b ry o id ,” a n d th e l a t te r “ De s-
m o b ry o id .” I n th e E rem o b ry a “ e a ch fro n d sp rin g s from a s e p a r a te node, m o re or
le s s d is ta n t from its n e ig h b o r, a n d is th e r e a r tic u la te d w ith th e rh iz om e ; so th a t,
w h en it h a s p a s s e d its m a tu r ity , it s e p a r a te s a t th e node, a n d le av e s b e h in d a c lean
co n c av e scar, . . . T h e e s s e n tia l d is tin c tio n b e tw e e n th e E r em o b ry a a n d De smo-
b ry a r e s ts in th e f ro n d s of th e fo rm e r b e in g articula ted w ith the axis, w hile th o s e
of th e la tte r a re adherent a n d continuous w ith ihe a x is ."
FERNS OF NORTH AMERICA. 11 7
in larger plants it is ovate or oblong-ovate in outline, and consists
of a variable number (five to twenty-five) of ample oblong-
lanceolate segments, which are separated by more or less rounded
and open sinuses, leaving a border a third of an inch wide along
each side of the general midrib. The two lowest segments are
sometimes distinctly separated from the rest, and are usually
slightly decurved. The central wing widens gradually upwards,
and at the apex of the frond is continued out into an undivided
terminal segment, which is nearly or quite as large as any of the
others. The segments are undulate or wavy, but entire, and have
a very narrow cartilaginous line-like border. The texture of the
frond is firm and sub-cartilaginous ; and the color is a glaucous-
green, becoming on the under surface paler and more decidedly
glaucous.
The venation is peculiar, and, as the synonymy shows, has
pu27,Ied those authors who have endeavored to divide up Polypo-
d nm into a dozen or more genera, based principally on differences
in venation. Each segment has a central midrib, and on each
side of it numerous reticulated veins and veinlets. Closely bordering
the midribs (both general and partial) is a series of narrow
elongated meshes or areoles. Outside of these arc one or two
irregular rows of broader areoles, with smaller ones variously
interposed. These larger areoles generally contain each a large
round or slightly oval sorus or fruit-dot, which is placed sometimes
at the apex of a single included veinlet, or more frequently
at the united extremities of two or even three included veinlets,
which, when the sori are in but a single row each side of the raidf
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