626 THE TEEN FAMILY. 



deeply pinnatifld ; the linear-oblong segments adhering to the main stalk 

 and usually connected with each other by their broad bases. Son rather 

 large, of a golden yellow, in two rows along the under side of the upper 

 segment. When bearing frait these segments are usually entire or nearly 

 so, and obtuse ; when barren they are often slightly toothed ; and mon- 

 strous states not unfrequently occur with the segments variously lobed or 

 branched. 



In sheltered places, on trunks of old trees, walls, moist rocks, and shady 

 banks, throughout Europe and Eussian Asia, from the Mediterranean to 

 the Arctic regions, and in North America. Common in Britain. Fr. sum- 

 mer and autumn. 



2. Beech Polsrpody. Polypodium Phegopteris, Linn. 

 (Eng. Bot. t. 2224, and P. Thelypteris, t. 1018.) 



Rootstock creeping. Fronds rather slender, 6 inches to a foot high or 

 rather more, iucluding their long stalks, broadly ovate-lanceolate and acu- 

 mmate in their general outline, once pinnate ; the segments deeply pinna- 

 tifld, narrow-lanceolate, gradually diminishing from the base to the end of 

 the frond, and all, except sometimes the lowest pair, adhering to the main 

 stem by their broad base. The midrib, principal veins, and margins of the 

 frond more or less hairy on the under side, by wMch this species may be 

 readily distinguished from the smaller specimens of the marsh Shieldfern, 

 wliich it sometimes resembles. Sori rather smaU, near the margins of the 

 lobes. 



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

 the Pyrenees and Alps to the Ai-ctic regions, and in North America. In 

 Britain, chiefly in western and northern England, Scotland, and Ireland. 

 Fr. summer <md autumn, 



3. Alpine Polypody. Polypodium alpestre, Hoppe. 

 {Pseudathyrium alpestre and P. flexile, Bab. Man.) 



Stock short, often forming several crowns. Fi'onds tufted, 1 to 3 feet 

 high, twice pinnate ; the segments numerous, oblong or lanceolate, deeply 

 pinnatifld, and sharply toothed, the larger ones usually about haK an inch 

 long. Sori cu'cular, without any indusium whatever : this character alone 

 distinguishes this plant from the smaller states of the lady Spleenwort 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 

 Scotland. Fr. summer. 



4. Oak Polypody. Polypodium Dryopteris, Linn. 

 (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 smaU lobes. 

 Segments thin, light green, obtuse, slightly crenate, quite glabrous. Sori 

 near the margins of the segments. 



