140 HISTORY OF BRITISH FERNS. 



Asplenium marmum, Linnccus. 

 The Sea Spleemcort. (Plate XIV. fig. 1.) 



This very handsome maritime evergreen Fern grows 

 profusely on our south-western rocky coasts and in the 

 Channel Isles, and extending to France and Spain, to 

 Madeira and the Canaries. In cultivation it thrives most 

 luxuriantly in the atmosphere of a damp hothouse, where 

 it forms, in a comparatively short time, a dense mass of 

 the deepest green, and often reaching a foot and a half in 

 length. In a cold frame, if kept closed, well-established 

 plants will continue in health, progressing slowly, and 

 never acquiring half the size of those grown in heat. In 

 the climate of London it does not prosper, nor, as far as 

 ■we know, survive, if planted on exposed rockw'ork. 



It is a tufted-growing species, with linear or linear- 

 lanceolate fronds, usually six or eight inches long, of the 

 deepest glossy green, with a smooth, rather short, dark- 

 brown stipes. The fronds are simply pinnate, with stalked 

 pinnse, connected at their base by a narrow wing, wliich 

 extends along the rachis ; their form is either obtusely 

 ovate or oblong, unequal at the base, the anterior base 

 being much developed, while the posterior is, as it were, 



