264 
THE FERN WORLD 
Irom six inches to a foot. They start from a thin, blackish, 
and extensively creeping rhizoma, the stipes— usually twice 
the length of the leafy portion — being smooth, pale green, 
and brittle. The colour of the fronds in their early stage is 
a delicate golden green — which becomes darker as they 
become older — and they consist of three branches standing 
nearly at right angles to one another, the upper one of the 
three — that carried on a continuation of the primary racliis — 
being the largest. Between the leafy portion of each branch 
and the point where at the top of the stipes they join, there 
is a clear space of stem. In the unrolling of the frond from 
the point of junction of the branches, the latter, before they 
are unfolded, present a curious appearance, like three little 
green balls on green wires. Each of the three branches 
when unfolded is triangular in shape ; pinnate at its base, 
and pinnatifid towards its apex, the pinnules set on its mid- 
stem in pairs, becoming shorter and shorter, and dually 
merging in an obtuse point. The basal pinnules of the 
branches are deeply cleft or pinnatifid, the lobes into which 
they are divided being oblong and blunt pointed. Whilst the 
pinnules on the uppermost of the three pimue or branches 
are equal in length, the pinnules of the two lower pinnae 
below the racliis or mid-stem of the branches are longer 
than those above it. At the point where the three branches 
are united the stem is thickened, giving the appearance 
of a little knot. The venation of the pinnules consists of a 
wavy mid- vein with alternate venules proceeding on each 
side of it to the margin, sometimes simple and sometimes 
forked, and bearing upon them near the margins of the 
pinnules the little light-brown, or sometimes golden, heaps 
of spore cases, arranged either in lines on each side of the 
mid-stems of the pinnules or on each side of the mid-veins of 
the lobes, according to the small or large size of the frond, 
and the development of its parts. 
