JarvucLry J'vt 1830.
Fig-1.
fra. g.
Y E R R U C A R I A isidioides.
W a rty -c ru ste d Verrucaria.
CRYPTOGAMIA Lichenes.
Gen. Char. Tubercles of a different substance rrom
the thallus, simple, convex, not expanding, but
furnished with a central pore, and inclosing a
somewhat gelatinous nucleus.
Spec. Char. Crust thick, tartareous, frustulose-areo-
late, yellowish brown. Tubercles small, globose,
pale, immersed in tumid roundish warts, except
the darker slightly prominent apex.
COMMUNICATED many years ago to Mr. Turner
by the late Miss Hutchins, who gathered it in Glengariff,
near Bantry. No other botanist appears to have met with
the species.
The plant forms indeterminate patches of considerable
extent, consisting at first of small, thin, plicate granulations
scattered on the rock. These are at length crowded into a
very uneven crust, which attains the thickness of a line in the
central parts, and is divided by narrow cracks iuto irregular
areolae, each composed of a congeries of convex warts, which
vary in protuberance, and are of a circular outline when perfect,
but often deformed by mutual pressure. The surface
is unpolished, greyish brown, nearly the same wet as dry,
often tinged with yellow in the younger parts of the patch.
The substance is extremely friable in the thick state of the
crust, of a somewhat fibrous fracture, and of a looser texture
at the base ; whence the areolae are liable to become
detached and to fall off, giving the patch a broken ragged
appearance.' The internal hue is grey or almost white, frequently
yellowish immediately round the tubercles. These
are very numerous, each occupying one of the convex warts
of the crust, which are usually concave at the summit, the
circumference forming a tumid ring at a little distance from