




60 THE BRITISH FERNS. 
Sitka, and the Slave River ; and thence through Columbia to Canada 
and the United States. The Polypodium intermedium, of Hooker 
and Arnott, from California is larger, and has the sori. somewhat 
oblong, and the veins occasionally, though very rarely, anastomosing 
near the margin; but as this occurs in so slight and inconstant a 
degree as if by accident, and the oblong form of sorus is met with in 
native forms of P. vulgare, we can scarcely believe it to be more 
than a variety of the common species. The same may be said of 
the Polypodium Karwinskianum, of A. Braun, a native of Mexico 
and Guatemala. 
The antiquated medicinal reputation of the Polypody seems to 
have little foundation in fact. It is supposed to be the “rheum- 
purging Polypody” of Shakspere. In some country places a 
decoction of the fronds is still used in the case of children as an 
expectorant remedy for colds and hooping cough, the mature fertile 
fronds, under the name of Golden Locks and Golden Maidenhair, 
being gathered for this purpose in autumn, and hung up like other 
herbs to dry; these are, when required for use, slowly boiled up 
with coarse raw sugar until the decoction becomes slightly bitter. 
The rhizome, which has a kind of bitter-sweet taste, when freshly 
infused, is reputed as a mild laxative; and, according to Dr. 
Deakin,* the Italians use common Polypody, in the form of 
decoction, as -a demulcent. M. Desfosses found the rhizomes to 
contain a sweet substance resembling sarcocollin, mannite, incrys- 
tallizable sugar, starch, albumen, malic acid, magnesia, and oxide 
of lime. Pliny states that the root dried and powdered, and snuffed 
up the nose, will consume a polypus; and according to Dr. Lindsay,+ 
the dried powdered rhizome was formerly applied externally as an 
absorbent, and for covering pills. 
The fronds of this Fern contain a considerable quantity of car- 
bonate of potass, which is sometimes obtained for use by burning. 
The ashes of the plant are then boiled in water, and the liquor is 
strained, and evaporated until the crystals are formed. 
This Fern is easily cultivated, but it requires that light porous 
soil should be used, and that the rhizomes should be kept on the 
* Florigraphia Britannica, iv. 39. + Phytologist, iv. 1065. 

