THE HARD PRICKLY SHIELD FERN 
2 73 
hedge-banks in shady lanes. Occasionally, seedling plants 
may be found growing on the sides of walls ; but it is 
under the deep shelter of over- arching trees, in a spreading 
wood, that it attains its finest development. 
Description. — From a stout and tufted rootstock; this 
Fern throws up a circlet of stout, rigid, and leathery textured 
dark-green fronds, which attain a height, according to 
circumstances, of from two to four feet. They are narrowly 
lance-shaped, tapering to a point at the apex, and tapering 
also towards the base of the frond. The stipes is con- 
siderably shorter than the leafy portion, and is furnished 
with densely-packed dark reddish-brown scales. Alternately, 
on each side of the rachis, are somewhat short, lance-shaped 
pinnae tapering to a point at their apices, and having on 
each side of their mid-stems, above and below, a row of 
somewhat wing-shaped pinnules attached by their bases, 
narroAved to a point, to the mid-stems of the pinnae. These 
pinnules are set on obliquely, their apices pointing outwards 
towards the tips of the pinnae, and sharply toothed or 
spurred at their outer edges ; their inner edges, however, 
next to and running in an oblique direction from the mid- 
stems of the pinnae, being smooth. Sometimes the pinnules 
are Avhat is called decurrent, that is, run together at their 
bases, This is always the case toAvards the tips of the 
pinnae, and more or less so nearer their bases ; though, in 
finely-developed plants, the basal pinnules are attached to 
the pinnae by short stems. The pinnules become smaller 
towards the apices of the pinnae, as the latter taper to a 
point. But it is curiously characteristic of this Fern, that 
the upper pinnule at the base of each pinna next the 
principal rachis is ahvays much larger, being both longer 
and broader than any of the others, and its apex frequently 
overlaps the base of the upper pinnule on the pinna next 
above it. One principal mark of distinction betAA r een Aculeatum 
