152 HISTORY OF BRITISH FERNS. 



but perhaps, from their crowded position, preventing its 

 proper formation. 



The name Ceterach is said to be an alteration of the 

 word Chetherak, which was applied to this plant by 

 Persian and Arabian medical writers. 



Ceterach officinarum, Willdenow. 



The Scaly Spleenwort, or Common Scale Fern. 

 (Plate I. fig. 1.) 



A dwarf, evergreen, distinct-looking, and very pretty 

 Fern, growing in tufts. The fronds when fresh are thick 

 and fleshy, and from this cause they are perfectly opaque 

 when dry. Their size varies according to the circum- 

 stances of their growth, from two to six inches in length, 

 rarely exceeding the latter. They grow on a short scaly 

 stipes, and are either pinnatifid, as is commonly the case, 

 or more rarely pinnate, the difference being, that in the 

 latter the fronds are divided rather more deeply than in 

 the former. The upper surface is a deep opaque green ; 

 and the under surface is densely crowded with rust- 

 coloured brown closely-packed overlapping scales, which, 

 being just seen projecting from the margin, and still more 

 fully in the exposed under-surface of the young partially- 



