1060 



THE FERN FAMILY. 



XV. WOODSIA. WOODSIA. 



Small, tufted, pinnately-divided Ferns, with brown scarious scales 

 or hairs on the under surface. Sori circular, surrounded by or inter- 

 mixed with a fringe of chaffy hairs, proceeding from the minute indu- 

 sium concealed under 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. Woodsia ilvensis, Br. (Fig. 1292.) 



(Eng. Bot. Suppl. t. 2616, and Poly podium hyperboreum, t. 2023. 



Stock densely tufted. Fronds spread- 

 ing, 2 to 4 or rarely 6 inches long, twice 

 pinnate, oblong-lanceolate in outline ; 

 the longer primary pinnas in the middle 

 of the frond 6 to 9 lines long, the lower 

 ones decreasing ; all pinnate or pinna- 

 tifid, with small obtuse segments, rather 

 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 mounlain-chains of central and 

 southern Europe, and central Asia. Rare 

 in Britain, and only in the mountains of 

 Scotland, northern England, and North 

 Wales. Fr. summer. The round-leaved 

 W. (W. hyperborea, Br.), usually con- 

 sidered as a distinct species, but probably 

 a variety only of the alpine W., differs 

 in its more tender texture, a greener colour, the segments shorter 

 and less deeply divided with more rounded lobes, and the scarious 

 scales less numerous, narrower and paler coloured. Its range is nearly 

 the same as that of the ordinary form, but it is generally much more 



Fig. 1292. 





XVI. TRICHOMANES. TRICHOMANE3. 



Delicate, half-pellucid Ferns, usually of a dark green. Fructifica- 

 tion consisting of little cup -shaped involucres, sessile upon or partly 



