180 Rhodora [SEPTEMBER 
The crown of the rhizome and the lower one-third of the stipes are 
covered rather densely, and the upper portions of the stipes more 
sparingly, with large rather persistent scales. These are sometimes 
over 1 cm. long, and up to 3 mm. wide, lanceolate, and contracted to a 
narrow base, so that in falling one leaves a very small scar which is 
almost round or like a minute inverted U. The scales are translucent 
and glossy, so that it is difficult to evaluate their true color. Seen 
against a white background, e. g. an herbarium sheet, they generally 
correspond to the “tawny” or “russet” shades of Ridgway’s Color 
Standards, Plate 15. Very rarely they are darker, approaching 
Ridgway’s “Mars Brown.” The cells of which they are composed 
are large enough to show plainly with a hand-lens of moderate power, 
and under a compound microscope appear as elongated, but scarcely 
fibrous cells about six times as long as they are wide. 
The stipes are commonly very short, one-fourth to one-third as long 
as the frond. The fronds themselves are lanceolate, widest in the 
middle, and tapering about equally in both directions. The lower 
pinnae are rather remote, in general strongly deflexed, and, though 
but little reduced in width, only one-fourth to one-half as long as the 
middle pinnae. 
In the details of the arrangement, form and cutting of the pinnules, 
this species, like all of its close relatives, is very variable, and innum- 
erable “varieties” have been named, sixty five of which are enumer- 
ated and described by Moore in his “ Nature Printed British Ferns.” ! 
The sori differ considerably in different specimens, and different 
parts of the same specimen, but have certain general characters which 
distinguish them clearly from those of the east American plants of 
this group (see Plate 123, figs. 1 and 2, also text-fig. 3, p. 175 and 
text-fig. 5, p. 176). They are uniformly short, very rarely reaching 
the length of 1 mm. Strictly asplenioid sori are rare, and are usually 
found only at the distal extremity of the pinnules, where the sori are 
considerably reduced in size. A,very common form is the sorus which - 
runs along the anterior side of the subtending vein for about 0.75 mm., 
and then crosses it without extending at all down the posterior side 
of the vein. In many specimens, horse-shoe shaped sori, and even 
round sori are found. In sori of the latter types, the indusium is 
1 Good figures, showing the general aspect of this fern may be found in the work just men- 
tioned, Folio ed. pl. 30-34, 8vo. ed. pl. 52-66, in Lowe, E. J., Our Native Ferns, pl. 35, also in 
his Ferns British and Exotic, v. pl. 29, and in Schkuhr, Ch., Kryptogamische Gewichse, pl. 58. 
