178 HISTORY OF BRITISH FERNS. 



been formerly found in Yorkshire. The same species is 

 widely distributed in the warmer parts of the world. 



The variety and elegance of this plant make it a favourite 

 species for cultivation. The conditions of success are, a 

 close atmosphere, shade, moderate warmth, constant but 

 not stagnant moisture, and a porous surface to which the 

 roots may cling. 



Among the many names which have been applied to this 

 plant, the following are the most likely to occur in English 

 books : Trichomanes speciosum, Trichomanes brevisetum, Tri- 

 chomanes alatum, and HymenopJiyllum alatum. 



Genus III. WOODSIA, R. Brown. 



THE Woodsias form a family group consisting of two di- 

 minutive kinds, which, however, possess much interest 

 among the British species on account of their extreme rarity. 

 These Perns are furnished with indusia, and by their peculiar 

 construction and position they may readily be known. The 

 peculiarities consist in their being not placed as a cover to 

 the sori, but attached underneath them ; when very young 

 they indeed enclose them, but subsequently in each case 



