BRITISH LICHENS

LECIDEA LECIDElACEM Gil
107. L. lapicida Ach. Moth. 37 (1803) pro partc.-Thallus
tal'tareous, thin, cracked-areolate, the areolro plane, light- or
ash-grey (K - or + y, then red; medulla I + blue). Apothecia
appressed or adnate, plane or slightly concave with a thin
prominent margin; hypothecium pale or brownish; paraphyses
loosely coherent, blue-greemsh-black or dark-brown at the
apices; spores ellipsoid, 9-13 fL long, 4-6 fl' thick; hymenial
gelatine blue then sordid with iodine.-Mudd Man. 209 pro parte;
Cromb. Lich. Brit. 81 pro parte (excl. vars.); Leight. Lich. Fl.
284 (exel. vars.); ed. 3, 289 (excl. var.). L. polycarpa Floerke ex
Sommerf. Suppl. Fl. Lapp. 149 (1826); Cromb. Lich. Brit. 82;
LClght. Lich. Fl. 283; ed. 3, 288. Lichen lapiC'tda Ach. Lich. Suec.
Prodr. 61 (1798).
Exswc. Johns. n. 350.
Th. Fries (Lich. Scand. 491, 493) places L. polyoarpa under L.
pantherina, of which he regards L. lapiCtda as a subspecies. The only
dIfference between the two is in the reaction with potash: in L. polyoarpa
the reaction varies from yellow to yellow followed by red, while
in L. lapicida there is usually no colour-reaction. Fries further states
that some specimens of Zapicida give no reaction in one part of the
thallus, while III another they tmge red. The reactIOn of our specimens
varies from a faint yellow to CrImson. .
Hab. On granitic and schistose rocks.-Distr. Found chiefly in
mountainous regions.-B. ]Jf. Cader Idris, Merioneth; Llyn Geironydd,
Trefriw; Nant Francon and Llanberis, Carnarvonshll'e; Malvern Hills,
Worcestershire; Red Screes, Reston Scar, and Pugh Crag, Westmorland;
Dent Hill, Cumberland; Ben Lawers, Perthshire; Morrone, Braemar,
AberdeenshIre; coast of Kincardineshire; Glen Nevis, Inverness-shue;
Clare Island, Mayo.
Var declinans Nyl. Lich. Scand. 226 (1861).-Similar to the
type but with a darker hypothecium and nearly ecrustaceOUB
thallus (K + yellow, then red).-Leight. in Ann. Mag. Nat. Rist.
ser. 3, xix. 403 (1867); Cromb. Lich. Brit. 81. L. polycarpa var.
declinans Leight. Lich. Fl. 284 (1871); ed. 3, 289. L. declinans
Nyl. in Flora IXI. 243 (1878).
Exsicc. Johns. n. 505.
Hab. On rocks in mountainous regions.-B. ]Jf. Ennerdale, Cumberland;
two doubtful specimens without spores from Ben Lawers, Perthshire,
and Braemar, Aberdeenshll'e, collected and named by Carroll.
108. L. lithophila Ach. Syn. 14 (1814).-Thallus tartareous,
whitish or ashy-grey, thin, cracked-areolate, the areolre plane
(K -, CaCI -) ; hypo thallus black. Apothecia numerous,
moderate in SIze or small, scattered or aggregate and angular,
plane, brownish-black, velvety and soft, almost black-pruinose
with a thin prominent flexuose margin; hypothecium colourless
or pale; paraphyses slender, loosely coherent, sometimes with a
greenish tinge, clavate, and blackish-brown at the tips (NO a + roseviolet);
spores ellipsoid, 9-15 fL long, 5-6 fL thick; hymenial
IT F