Cijstopteris .] 
FERNS. 
31 
Syn. — Woodsia hyperborea, Br., IIoo/c., Smith , E. FI., Galph. — Acrostichum 
alpinum, Bolt. — Ceterach alpinmn, Lam., Decan. — Polypodium hyper- 
boreum, Swz., / Filld ., Spreng., Smith, in E. B. — Woodsia alpina, 
Newm., 1854. 
Fig. — E. B. 2023. — Bolt. 42. — l Linn. Trans’ vol. xi. — Pink. Phyt. 89, f. 5. 
Des. — Rootstock perennial, fibrous, black, tufted, and very long, 
giving rise to many linear-lanceolate pinnate leaves, from 2 to 4 
inches high. Lower part of the stem covered with light-brown 
capillary scales. Leaves with eight or ten pairs of pinnae, only the 
two or three lower pairs opposite, and these not constantly so, all 
nearly smooth, bluntly triangular, deeply crenate, or cut into two 
or three segments on each side. The upper half of each pinna 
larger than the other, and in luxuriant specimens cut into pinnules 
near the stem. Sori from six to ten on each pinna, placed near the 
edge, light brown, very large, and often confluent. 
From the very numerous segments of the indusium, a sorus appears like a 
bunch of hairs. The distinctive character, however, is chiefly the less cut, 
shorter, and more alternate pinnae. The plant known as Woodsia hyperborea 
by gardeners is in reality a large variety of Woodsia Ilvensis, known as such 
before the separation of the present from that species. 
Sit. — Found only on the highest rocks and mountains of Wales and Scotland. 
TIab. — B en Lawers, Dr. Murray and Mr. W. Wilson. Clova Mountains, Mr. 
G. Don. Craig Chailleach, Perthsli., Mr. Maughan. Mael Ghyrdv, Perthsli., 
and on Snowdon, below Bwlch-y-Saeth (Clowwyn-y-Garnedd), at an elevation of 
2500 feet and upwards, very sparingly, Mr. W. Wilson. Mr. C. C. Babington 
says, “ I was not able to find this plant on Glydr Fawr, Caernarvonshire, July, 
1835, although in company with J. Roberts, Esq., of Bangor, who knew its 
station well. It is, I fear, exterminated in that place.” I searched for it in the 
same spot in 1837, and a botanical friend in 1840, but both without success. 
Geo. — Lapland, Germany (?), France (?) {Swz.), Lulea, in Lapland ( Sprang .), 
Canada, and high mountains of Pennsylvania and Virginia. 
CYSTOPTERIS, Bern. BLADDER-FERN. 
(K votiq, a bladder, nrspig, a feni ; the indnsia being like bladders.) 
A, one of the pinnae of the leaf of Cystopteris fragilis. B, a pinnule magnified. 
C, young sori and indusia. D, sorus cut perpendicularly. E, theca. F, spores. 
G, indusium magnified from Bauer’s ‘ Genera Filicum.’ H, ditto from Scholl’s 
* Genera Filicum.’ 
The genus is distinguished by its indusia being inflated like bags, not being 
attached by a central column, but only by the edge nearest this rachis, and 
finally either quite bent back, or thrown off altogether. They first open on the 
to p, or on the side nearest the apex of the leaf or pinna. 
