112 
HISTORY OF BRITISH FERNS. 
ones, but closely resemble those of cristata, the fertile ones 
having much more the appearance of those of the mr, 
spinulosa, only that they are narrower, and have narrow 
pinnm. The outline of these fertile fronds is narrow 
lance-shaped, the pinnm having a narrow tapering form, 
and the pinnules being oblong-pointed, with rather deep, 
serrated, marginal notches, the serratures terminating in a : 
fine point. The midvein of the pinnules is tortuous, 
giving oif branched lateral veins, the anterior of which 
bears a sorus, so that these latter are placed in two regular 
lines lengthwise on each pinna ; the sori are produced from ; 
the base to the apex of the frond, and are covered by even- i 
margined, kidney-shaped scales or indusia. The barren i 
fronds are broader, usually shorter, less erect, and their 
pinnules are of a broader, blunter form, and more closely ' 
placed, than those which are fertile. Sometimes after the ^5 
growth of the first set of fertile fronds others spring up ‘ 
which are also fertile, but have the appearance described I 
above as peculiar to the barren ones ; these fronds being 
undistinguishable from cultivated fronds of L, cristata. 
This plant is found on boggy heaths, generally in company 
with cristata and spinulosa ; but it is comparatively rare, i 
The variety spinulosa, known as the Narrow Prickly- 
