riLiCES. 637 



in our Floras as having formerly existed on an old wall, at Low Lay ton, in 



Essex. 



2. Mountain Bladderfern. Cystopteris montana, Bernh. 



Eoctstock creeping. Fronds growing singly, twice or thrice pinnate, 

 broadly triangular or rhomboidal in general outline, the pinnas of the lowest 

 pair being considerably larger and more divided than the others, as in the 

 Oah Polypody, which this plant much resembles. It is however of a more 

 deheate textm-e, only 6 or 8 inches or rarely a foot high, includmg the long 

 slender stalk ; the pinnas are mostly alternate, with more divided, smaller 

 segments, and the slender indusium over the sori is easily seen imder a mag- 

 nifying-glass when young. 



In moist, alpine situations, in northern and Arctic Europe, and in the 

 great mountain-ranges of central and southern Europe, in the mountains of 

 north-western America and Eamtchatka. In Britain, only in a few locali- 

 ties in the Hielilands of Scotland. Fr. summer. 



XV. ■WOODSIA. WOODSIA. 



Small, tufted, pinnately-divided Ferns, with brown soarious scales or hairs 

 on the under surface. Sori eu'cular, surrounded by or intermixed with a 

 fringe of chaffy hairs, proceeding from the minute indusium concealed imder 

 the sorus. 



A small genus, still more strictly confined than the last to high northern 

 or southern latitudes, or to great elevations. 



1. Alpine 'Woodsia. ^Voodsia ilvensis, Br. 



(Eng. Bot. Siippl. t. 2616, and Polypodium hyperboreum, t. 2023.) 

 Stock densely tufted. Fronds spreading, 2 to 4 or rarely 6 inches long, 

 twice pinnate, oblong-lanceolate in outline ; the longer prunary pmnas in 

 the middle of the frond 6 to 9 Unes long, the lower ones decreasing ; aU 

 pinnate or pinnatifid, with small obtuse segments, ratlier thick, green and 

 glabrous, or hairy above, more or less covered underneath with brown 

 scarious scales or chaffy hairs. 



On alpine rocks, in northern and Arctic Europe, Asia, and America, and 

 in the great movmtain-chains of central and southern Europe, and central 

 Asia. Rare m Britain, and only in the mountains of Scotland, nortliern 

 England, and North Wales. Fr. summer. 



XVI. TRICHOMANES. TRICHOMANES. 



Delicate, half-peUucid Ferns, usually of a dark green. Fructification con- 

 sisting of httle cup-shaped involucres, sessile upon or partly immersed in 

 the edge itself of the frond. In the centre of the involucre is a little 

 bristle, often projecting beyond it, round the base of which are attached the 

 minute capsules or spore-cases. 



A large genus, widely spread over the warmer regions of the, globe, but 

 more especiallv in tropical America. 



3 I 



