126 VII. LASTREA. 
the rachis being in fact folded laterally into two or three 
short lengths, while the extreme point is cireinate. When 
quite young they are often but not always glandular, 
especially on the under side. The stipes in the full-grown 
plant, is very stout at the base, and there thickly clothed 
with lanceolate alternate sharp-pointed scales, which, in 
most of the varieties, are very dark coloured and opaque 
down the centre, paler and nearly transparent at the mar- 
gins. The fronds are usually ovate-lanceolate in outline, 
but vary from almost triangular to almost lanceolate. The 
approach to the deltoid form, is perhaps confined to the 
fronds of young or starved plants, in which it certainly 
most frequently occurs. The fronds are twice or thrice- 
pinnate, the pinn standing in nearly opposite pairs, which 
are most distant from each other in the lower part of the 
frond. The pinnae vary in form as well as in size, the 
longest measuring from three to six or in very large 
plants nine inches in length ; and the lowest being often 
nearly triangular, broader as well as shorter than the three 
or four next above, the upper ones then becoming gradu- 
ally narrower, and shorter ; they are bipinnate below, and 
pinnate near the apex of the frond. The larger pinnules 
on the lower part of the frond are attached by a short 
slightly winged stalk, whilst those towards the point of 
the pinnae, and in the upper part of the frond gradually 
become less distinctly stalked, and are finally decurrent. 
The inferior basal pinnules, especially those of the lower 
pinna;, are much larger than the superior pinnules of the 
same pinnae, and hence all the lower pinnae acquire an 
oblique figure which is gradually lost in the upper part of 
the fronds. The pinnules are variously divided, more or 
less convex ; those at the base of the pinnae are almost or 
quite pinnate, further up they are more or less deeply pin- 
natifid, and towards the apex toothed ; all the lobes are 
sharply serrate, the teeth ending in a short spine-like 
point. The venation selecting a central pinnule from a 
central pinna is arranged in this manner : Each lateral 
