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H a b .— In the United States from Illinois and Wisconsin to Utali,
Colorado, New Mexico, and Arizona. In British America, collected by
B o u r g e a u at the eastern base of the Rocky Mountains, near lat. 51°.
Fort Independence, Mo., N u t t a l l ! It grows in dense tufts on dry exposed
rocks and cliffs.
D e s c r i p t io n . — Root-stocks rather short, creeping, forming
a matted mass; the chaff narrow and somewhat crisped, deep
cinnamon-brown, with a blackened midrib; fronds densely clustered,
two to four inches long, or sometimes very much smaller ;
stalks about as long as the frond, very slender, wiry, but rather
fragile, very dark brown or almost black, scantily furnished with
spreading, pale-fulvous, jointed hairs. In the larger specimens
the fronds are fully tripinnate; the pinnæ triangular and opposite
at the base of the frond, but towards the apex gradually become
ovate, and are alternate and crowded. The ultimate pinnules are
very much crowded, very minute, — scarcely half a line in diameter,—
rounded, or slightly obovate; the terminal ones rather
larger, and obscurely lobed. The upper surface is scantily provided
with whitish webby hairs ; the lower surface heavily covered
and obscured with pale-fulvous matted wool, the fibres of which
are flattened and plainly articulated. The involucres can be seen
only by carefully removing the wool, and are then found to be
almost continuous round the lobule, and formed of its scarcely
changed herbaceous margin. The general color of the plant is
of a pale grayish-green, intermingled with light brown.
This fern was originally discovered in Missouri by Thomas
Nuttall ; and his specimens, with his manuscript name, are preserved
in the Hookerian herbarium.
FERNS OF NORTH AMERICA.
In writing the “ Species Filicum,” Sir W. J , Hooker seems
to have confounded it with Ch. vestita of Swartz ; but his description
and figure apply to the present plant. Dr. Fee’s figure is
also characteristic, though representing a specimen not so large
as we commonly see. Those persons who call the plant Cheilanthes
gracilis (Riehl) are only perpetuating an error, or lapsits
calami, oi Mettenius in quoting F é e ; for Fée says plainly, “ C/z«-
lanthes vestita (Riehl, non Sw.), No. 529.”
Plate VI., Fig. 2 .— Cheilanthes lanuginosa, of natural size, with a
small portion considerably enlarged, the woolly hairs removed to show
the narrow involucre.
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