A S P I D I U M spinulosum.
Lesser Crested Shield-fern.
CRYPTOGAMIA Filicés.
G en. Char. Fructifications scattered, in roundish
dots, not marginal. Involucrum umbilicated,
bursting almost all round.
S pec. Char. Frond nearly bipinnate; leaflets decurrent,
elliptical, serrated or pinnatifid, their segments tipped
with little spines. Common stalks smooth. Ribs
zigzag.
Syn. Aspidium spinulosum. Sm. FI. Brit. 1124.
Polypodium spinulosum. Retz. Prod. 250. FI. Dan.
t. 707. With. 778. Hull. 239. Sym. 191.
P. n. 841. Muller. FI. Fridr. 193. t. 2. f . 2.
Filix pumila saxatilis altera. Pluk. Phyt. t. 119. f . 5.
A^xR. J. T. Mackay of Dublin gathered this specimen last
September in a cavern on Spike Island, near Cove, below
Cork, Ireland. Dr. Scott has found the same in the north
part of that kingdom. We never saw it before except in
Mr. Rose’s herbarium. Muller and Plukenet have figured it
well, but Dr. Withering first made it known as a British
plant. Probably it may have been confounded with the following
species.
The root is creeping. Fronds about a foot high, each with
a long slender stalk, which is quite smooth except its very
base. The primary divisions are so deeply pinnatifid as to be
almost pinnate; their lobes elliptical, sharply serrated or pinnatifid,
thin and delicate, each incision tipped with a spine.
The rib of each pinnula is very much waved or zigzag. Dots
of capsules rather small, with a circular covering.