74 



BRITISH FERNS. 



chance to visit the spot. If I hereafter revisit this wall, it v^ill 

 be mortifying to me to find that I have caused the destruction 

 of the habitat. 



The roots are very long, fibrous, crooked, and intertwined, and 

 together with the rhizoma, which is very large and tufted, form 

 an amazing bulk ; a plant I procured at Llanrwsthad upwards of 

 three hundred fronds, and the mass of roots and rhizoma, after 

 shaking off* a good deal of earth, weighed several pounds. The 

 fronds make their appearance in March and April, arrive at 

 maturity in August, and remain green throughout the winter; 

 they grow in a horizontal position from a perpendicular surface : 

 the fronds represented in the preceding page are in the natural 

 position, and of the natural size. 



The form of the frond is elongate, lanceolate, and furnished 

 laterally with one or two short bifid teeth or serratures, and the 

 apex also terminates in a bifid point : it diminishes imperceptibly 

 towards the base, and there terminates in a smooth rachis, which 

 is black at the extreme base. 



The veins are nearly simple, 

 and few in number, one running 

 into each serrature. The thecae 

 are attached to each vein in a 

 continuous line, covered at first 

 by an indusium of similar shape, which opens towards the mid- 

 vein of the frond, and, as the thecas swell, is thrown back, and 

 finally lost, and the lower surface of the frond presents a con- 

 tinuous mass of thecae. 



