
GENERA AND SPECIES. 35 
PLATE IV. 
POLYPODIUM VULGARE. Linnzus. 
COMMON POLYpPopy. 
The Common Polypody is a typical species, having the 
characteristic creeping root-stock of the genus. It is gener- 
ally found growing among the mosses on overhanging rocks, 
although it is rarely confined to any special habitat. In 
England and Scotland it often grows on the trunks of trees, 
and sometimes even upon the thatched roofs of cottages. 
Some specimens in my own collection were found on the 
banks of Loch Lomond, Scotland, growing on a dry stone 
wall, the thick rhizomes imbedded in the moss below. This 
fern has a wide geographical range, and in the United States 
belongs to the Appalachian division of Mr. Redfield’s classi- 
fication. In Kentucky it grows to perfection in Rockcastle 
and Laurel counties; also in Madison County (Short). I 
visited the former county in the middle of March, and was 
surprised to find this fern in such abundance, especially at 
this season. Every sheltered rock, whether on the hill- 
sides or along the banks of streams, was literally covered. 
Thickly imbedded in a carpet of moss, it can be detached 
from the overhanging rocks in great masses. ‘The average 
size of the full-grown plant is from eight to ten inches. 
The root-stock is densely covered with chaffy scales. The 
frond is oblong, somewhat lanceolate or alternate pinnatifid, 
the leafy portion commencing a little below the upper half 
of the frond; the divisions linear oblong, with a wavy 
outline, sometimes slightly serrated. The whole plant is 
smooth, and always has a fresh, dark evergreen appearance. 
In sheltered localities it remains green all winter. The . 
articulation of the stem is shown in the illustration. 
