7o 



BRITISH FERNS 



this species of leaves rubbed down to dust with plenty of coarse 

 silver sand. Its fronds spring from a tufted rootstock, and have a 



black, shiny stalk, whence 

 the name. Its subdivisions 

 vary considerably in the 

 direction of greater obtuse- 

 ness or acuteness, the 

 latter appearing to de- 

 pend to some extent on 

 climate. The imported 

 Fern fronds sold in our 

 markets as the "French 

 Fern " are of this species, 

 and are always of the 

 acute variety (Fig. 23). 

 Several marked varieties 

 have been found. 



Grandiceps (Fig. 24). — 

 Heavily crested at frond 

 tip, and with fan-shaped, 

 serrate pinnse. Found in 

 Ireland by the Rev. R. 

 Travers Smith. A similar 

 Fig. 24. Asp. ad. nig. grandiceps. form was found in Devon. 



Lineare. — A form found by the writer in Cornwall, with very 

 narrow fronds and linear subdivisions. 



Fig. 25. Asp. ad. nig. microdot*. 



Microdon (Fig. 25).— Found in Guernsey ; is a counterpart of 

 the variety of Asp. lanceolalum similarly named ; it is presumably 

 a plumose form, and is, we believe, barren, the spores, though 

 apparently plentiful, being aborted. 



