POLYPODIUM. 
151 
THE ALPINE POLYPODY. 
Polypodium alpestre .—Hoppe. 
A Lady-fern looking plant, 
but having circular (minute) 
sori, which are not covered 
with an indusium. It is only 
found on mountain* of from 
2,000 to 4,000 feet elevation. 
'I he fronds are somewhat lan- 
ceolate and bipinnate. Usually 
20 inches in length, but some- Fig. 44. — Polypodium alpestre 
times double this size. The (D na, showing fructification), 
habit is erect, and the fronds are deciduous. 
First recognised as British by Mr. Watson, in 1S41. It has been 
found on the Clova mountains by Mr. Backhouse, and Mr. G. 
Lawson ; on the Deeside mountains, by Mr. T. Westcombe and 
Mr. Backhouse ; on Ben Aulder, by Mr. Watson ; Lochnagar, by 
Mr. Croall ; and on Ben Lawers, by Mr. Fraser and myself. It 
appears to be abundant though local. It is exclusively a Scotch 
fern, as far as the United Kingdom is concerned ; but it is found 
in Switzerland, Germany, Russia, Norway, Sweden, Lapland, and 
the Caucasus. 
Varieties. 
1. flexile, Newman. Found in Glen Prosen (Clova). Handsome 
and distinct. Length, 6 to 18 inches. Very narrow ; the pinnae 
shorter, and the pinnules less in number. Sori only near the base 
of the frond. 
2. laciniatum, Stansfield. Raised from spores by Mr. Stansfield. 
More dense than flexile , and the pinnae laciniate. 
3. lanceum, Moore. Found on Clova by Mr. G. Lawson; and 
on Lochnagar by Mr. Croall. 
4. tripinnatum, Moore. Found at the Wells of Dee by Mr. G. 
Lawson. Fronds large, tripinnate, and the pinnules very large. 
THE COMMON POLYPODY. 
Polypodium vulgare. — Linnceus. 
Fig. 45. — ..ooe of Polypodium vulgare. 
The common Polypody cannot be confused with any other 
British fern. The stout, firm fronds attached to the thick, creeping 
rhizoma in such a manner that they separate from it, like leaves 
