54 FERNS OP GREAT BRITAIN. 



forming two lines on eacli pinnule. The same mode of 

 veining is found in the more divided pinnules, the 

 smaller veins being more numerous. Kidney-shaped 

 indusia, with uncut margins, cover, the clusters. This 

 species is by many writers considered but a variety of 

 the following. It is also the Aspidium spinuldsum or 

 Lophodium spinSsum of other writers. 



8. L. dilatdta (Broad Prickly -toothed or Crested 

 Fern). — Fronds arched, lanceolate or triangular, twice 

 pinnate ; pinnules pinnate or pinnatifid ; indusium kidney- 

 shaped. This pretty fern, which is one of the most 

 compound of our native species, is usually about two or 

 three feet in height. Its luxuriance, however, depends 

 greatly on the spots on which it grows, and it sometimes 

 attains the height of five feet, becoming under these 

 circumstances more branched, and acquiring a deeper 

 green hue. Several species of Lastrea grow upright, or 

 nearly so, but the fronds of this fern fall into graceful 

 arch-like forms. The outline of a well grown and luxu- 

 riant plant is egg-shaped and lanceolate, varying to a 

 narrow lanceolate figure, and in young or half-starved 

 specimens becoming short and broadly triangular. The 

 stalk, which is much thicker at the base than in the 

 upper part, is clothed with long pointed scales, which 

 are in the middle of dark brown colour, but are clear 

 and paler at the margins. The twice pinnated frond 

 has narrow pinnae; the pinnules at their base being 

 often so deeply divided as to be again pinnate; while 

 the others are pinnatifid, except at the upper parts, 

 where they are merely toothed. The margins of all are 

 serrated and spinous. 



