FILICES. 



1039 



In moist situations, in hilly districts, in Europe and Russian Asia, 

 from the Pyrenees and Alps to the Arctic regions and in North Ame- 

 rica. In Britain, chiefly in western and northern England, Scotland, 

 and Ireland. Fr. summer and autumn. 



3. Alpine Polypody. Polypodium alpestre, Hoppe. 



(Fig. 1263.) 



(Pseudathyrium alpestre and J?, flexile, Bab. Man.) 



Stock short, often forming several 

 crowns. Fronds tufted, 1 to 3 feet 

 high, twice pinnate ; the segments nu- 

 merous, oblong or lanceolate, deeply 

 pinnatifid, and sharply toothed, the 

 larger ones usually about half an inch 

 long. Sori circular, without any in- 

 dusium whatever : this character alone 

 distinguishes this plant from the 

 smaller states of the lady Sjpleenwort 

 and from some forms of the broad 

 Shieldfern, which it closely resembles 

 in all other respects. 



In the mountains of Europe and 

 western Asia, from the Alps and the 

 Caucasus to the Arctic regions. In 

 Britain, only in the Highlands of Scot- 

 land. Fr. summer. 



Fig. 1263. 



4. Oak Polypody. 



Polypodium Dryopteris, Linn. 

 (Fig. 1264.) 



(Eng. Bot. t. 616. Oak Fern.) 



Rootstock creeping, rather slender. Fronds slender but erect, on 

 long stalks, broadly triangular or rhomboidal in their general outline, 

 the leafy part 4 to 6 inches long and at least as broad, twice pinnate, 

 or rather, in the first instance, ternate ; the lower pair of branches 

 or pinnas on slender stalks, each often as large and as much divided as 

 the rest of the frond ; the others much smaller and less divided, the 

 terminal ones reduced to small lobes. Segments thin, light-green, ob- 

 tuse, slightly crenate, quite glabrous. Sori near the margins of the 

 segments. 



