POLYPODIUM. 
Ill 
POLYPODIUM. 
Gen. Char. “ Sori dorsal, subglobose or oval, destitute of 
involucre. Yeins free (as in all the British species) or anasto- 
mosing .” — Sir W. Hooher. 
2 . Polypodram vulgare, L. Common Polypody. 
Caudex stout, widely creeping, scaly. Fronds ovate-oblong. 
Sori round, placed in a row on either side the mid- vein. 
The name of this well-known fern is formed from two 
Greek words, polys , many, and pous , podos , a foot ; and 
is applicable because of the many rootlets thrown out 
from the caudex. 
The form of the frond is very variable,— we sometimes 
find it eighteen inches long, 
while the plants that grow on 
old walls have often fronds 
not more than three inches 
in length. The caudex creeps 
horizontally, becoming inter- 
laced and matted when left 
long undisturbed, and densely 
clothed with narrow, glossy 
brown scales. The frond is 
pinnate, the pinnae nearly 
equal, opposite, and slightly 
waved or jagged at the mar- 
gin. Each pinna has a mid- 
vein, from which branches 
issue, and the fructification is 
situated at the point of the side veins. 
Common as this fern is, and familiar to every one 
who has eyes to see with, it never fails to be noticed 
wdth favour. Lending to the decaying trunk a new 
