a 
GENERA AND SPECIES. I4I 
Pearse. LVI. 
BOTRYCHIUM VIRGINIANUM. Swartz. 
VIRGINIA MOONWORT. 
This species is undoubtedly the handsomest of all our 
Moonworts. ‘The sterile branch is sessile above the middle 
of the common stalk, and ternate, the lower pinnz spread- 
ing, forming a broad triangular frond. About the begin- 
ning of May, if growing in a rich soil, the plant possesses 
a thick, fleshy texture, which is lost when it attains matu- 
rity, becoming thin, delicate, and membranaceous. It is 
very variable, both in form and size. I have seen speci- 
mens two feet high and sixteen inches broad, measured 
from the points of the lower pinne. It is common in 
Kentucky in damp, rich woods, where there are plenty of 
moisture and leaf-mold. In a dry, sterile soil it becomes 
slender and dwarfed, whence Pursh was led to establish a 
new species, the B. gracile.* It is found very generally 
throughout the United States and Canada, though restricted 
by Mr. Redfield to the Appalachian region. Singularly 
enough this fern was placed by Linnzusf among the 
Osmundas, which differ from it very widely, both in gen- 
eral appearance and in the peculiar mode of fructification. 
The Plate represents a portion of the plant, natural size, 
cut off at the point where the sterile branches off from the 
fertile frond. The fertile frond, in the Plate, does not show 
the fruit in such profusion as would appear on a better de- 
veloped plant; yet it is sufficient to enable the student to 
determine the species without difficulty. 
* See Pursh, Flor. Am. Septen. vol. ii, p. 656. 
ft See Species Plantarum, 1579. 
