12 POLYPODIUM ALPESTRE. 



from three to four thousand feet above the sea, and extending 

 downwards to two thousand feet. It has only been found in 

 the Highlands of Scotland, in the counties of Perth, Forfar, 

 Inverness, and Aberdeenshire. Having a very similar appearance 

 to some forms of the Lady Fern, it was confounded with 

 that species, and therefore passed over without sufficient notice 

 until recent botanists detected its true difference. 



This Fern is widely spread in Europe, being a native of 

 Germany, Switzerland, Lapland, Russia, Norway, Sweden, and 

 the Caucasus. 



Although so recently introduced, there arc several distinct 

 varieties already in cultivation. 



It is a pretty, delicate-looking, hardy Fern, and groAvs 

 readily in a well-drained, loamy, porous compost. It is 

 propagated by spores, and also by divisions of the tufted 

 caudex. 



As yet it has not been discovered either in England, 

 Wales, or Ireland. 



The fronds, which are lanceolate in shape, and herbaceous, 

 attain a length of from twelve to forty inches, the usual 

 length being twenty inches. The habit is upright, and the 

 colour deep green. Bipinnate, sometimes tripinnate. Pinna3 

 lanceolate-acuminate; pinnules oblong-ovate, profoundly pin- 

 natifid, segments serrate. The frond is broadest in the centre, 

 narrowing to the base and apex. The stipes is short, not 

 one fourth the length of the rachis; on it are scattered pale 

 brown scales. 



Veins consisting of a tortuous mid-vein, from which proceed 

 into each segment a pinnate branch; venules simple, extending 

 nearly to the margin, and bearing sori considerably below 

 their apices. 



Sori circular and minute. Spore-cases numerous, and of a 

 brown colour. 



Caudex perennial, brief, and decumbent. Fronds annual, 

 aj)pearing at the end of April. 



The several varieties arc: — 



Var. Flexile. — Occurring only on the Clova ^Mountains, where 

 it was found in Glen Frosen, by Mr. Backhouse. It is very 

 handsome and distinct, being more slender and flaccid, the 

 pinnsD shorter, and the pinnules much less in number. The 



