128 SWISS FERNS. 



handsome circular tufts, three or more feet high ; oblong- 

 elliptic and bi-pinnate lobes blunts oblong, rather toothed. 

 Forests. One of the most common British Ferns. 



A. (Lastrea) rigidum, spinulosum, dilatatum, or crista- 

 tum. All these are considered by some to be variations 

 of Filix-mas. A. dilatatum is specially variable, and is very 

 common ; its lobes are often furnished with spiny teeth. 

 The frond of A. rigidum is stiff er. 



7. Phegopteris, or Polypodium. 



Fronds with long stalks rising altogether from six to 

 twelve inches, pinnate, or ternately divided. 



P. polypodioideSj or Polypodium Phegopteris, Beech-Fern. 

 Fronds oval, lanceolate, and pointed, once pinnate. The 

 two first lobes of each segment are united at the base with 

 the segment opposite. It may always be known from 

 having the lowest pair of leaflets turned down in an oppo- 

 site direction from the others. It is more or less hairy 

 on the under side. Forests. 



P. or Polypodium Dryopteris, Oak-Fern. Fronds ter- 

 nate, each division twice pinnate, from six inches to a foot 

 high. Plant slender, smooth ; segments thin, of a pretty 

 light-green colour, with the sori near the margin. Rocks. 



