6c. [ 2520 ]
C A L I C I UM sessile.
Slack Sessile Calicium.
CRYPTOGAMIA Algce.
Gen. Char. Receptacles capitate, stalked, totally different
in substance and colour from the crust, with
a border of their own substance ; disk powdery.
S p e c . C h a r . Crust not discoverable. Receptacles
nearly sessile, pear-shaped, black, polished, with
a thick inflexed margin, and black powder.
Syn. Calicium sessile. Pers. Tent, suppl. 59. (Ach.)
Turn. & Borr. Lich. Brit. v. 1 . 128.
C. stigonellum. Ach. Meth. 88.
Lichen gelasinatus. With. v:.4. 8. t. 31. f. 1 . Hull.
285.
Sphaeria sphincterica. Sowerb. Fung. t. 386. ƒ . 1;
excluding th e reference to Bulliard.
T h is remarkable production was first made known in England
by Dr. Withering, who described it as a new Lichen, not adverting
to its being a parasite on the well-known L.perlusus, t. 677.
Many have, with more probability, taken it for a fungus; but
Mr. Turner and Mr. Borrer retain it (after Persoon) in Calicium ;
a measure justified by its near affinity to our Lichen microce-
phalus, which is properly a Calicium also.
Its chief singularity is the total absence of a crust, at least at
the period of its fructification. The receptacles are scattered
over the tumid unequal crust of the plant which is their foster-
mother, into which they are a little sunk. Each looks like a
grain of the finest gunpowder, but under a microscope proves
pear-shaped, polished, with a very short solid stalk, the disk
small, deeply hollow, producing a black opaque powder. The
margin is said to be occasionally white,