ill
marks of distinction. As this book is intended for the use
of those who are only likely-—at least whilst they require its
—to study the smaller group, we shall endeavour to show
them how to understand the minuter differences which serve
to separate this series of Crested Eerns into several recognizable
species ; and for this purpose shall first enumerate
the leading features of distinction :—
Lastrea cristata grows with very erect, narrow, oblong
fronds, whose deltoid pinnæ are not quite divided down to
the central rib, and the lobes into which they are separated
are attached by the whole width of their base, and are oblong
with a rounded apex. The stipes is sparingly furnished
with broad, obtuse, membranous, whole-coloured scales.
Lastrea uliginosa has two or three sorts of fronds ; one
set, the earlier ones, having much resemblance to those of
the preceding, the other sets producing fructification, being
bipinnate at the bases of the pinnæ, the fronds narrow-
oblong, the lobes tapering to a point, and the scales of the
stipes broad, blunt, and whole-coloured. This connects
cristata with spinulosa.
Lastrea spinulosa grows erect, has narrow, lance-shaped,
bipinnate fronds, and whole-coloured blunt scales to the
stipes. It is broader and more divided than the foregoing.
Lastrea dilatata grows more spreading, has still broader
or ovate lance-shaped fronds, and the stipes is clothed with
lance-shaped scales, which are darker-coloured in the centre
than at the margins. This is a very variable plant.
L a s tr e a fmnisecii grows spreading, and has fronds smaller
than the last; they are triangular, bipinnate, and the segments
have their edge carved back so as to present a hollow
surface to the eye; the scales of the stem, are narrow,
pointed, and jagged.
Lastrea cristata itself, the Crested Eern, is not very elegant,
but of considerable interest on account of its rarity.
I t forms a thick stem or root-stock, from which a limited
number of narrow, very upright fronds arise early in May,
and attain the average height of a couple of feet. ^ The
fronds are destroyed in autumn by the frosts. ^ Their outline
is linear-oblong, that is, from a narrow width at the
base of the leafy portion—say two and a half or three inches
in the case of fronds of the average height—the margins
run nearly parallel almost to the apex, where they narrow
into a blunt point; they are supported by a stipes whicn
rather exceeds a third the length of the entire frond, is proportionally
stout, and maintains this proportion upwards
through the leafy portion of the frond; on the lower part it