BRITISH LICHENS

LECIDEA LECIDEACElE 45
the S. Grampians, Scotland, and N. lreland.-B. ]JI. Cader ldris,
Merioneth; Ben Lawers, Pcrthshire; Morrone, Braemar, Aberdeenshire;
Invermoriston, lnvernessshirc; Armagh; near Belfast, Antrim;
Doughruagh Mt., Galway; Dunkerron, Kerry.
60. L. fuscorubens Nyl. ex Salw. in Trans. Edin. Bot. Soc. vii.
551 (1863).-Thallus effuse, very thin, smooth, sordid-greyish
or yellowish (K -, CaCI - ) ; often obsolete. Apothecia
small, sessile, plane, marginate, then convcx and immarginate,
brownish or black, reddish-brown when moist; hypothecium
thick, brown; epithecium pale-reddish; spores ellipsoId, 10-14 (.L
long, 5-9 (.L thick; hymemal gelatine bluish then wine-red with
iodine.-Cromb. Lich. Brit. 68 pro parte; Leight. Lich. Fl. 300
pro parte; ed. 3,310. L. ochracea Wedd. in Mem. Soc. Sci. Nat.
Cherb. xvii. 369 (1873); Cromb. in Journ. Bot. xiii. 141 (1875);
Leight. Lich. Fl. ed. 3, 251. L. subochracea Nyl. Lich. Env.
Paris Suppl. 5 (1897). Biatom fuscorubens Nyl. in Bot. Not.
1853, 183 pro parte. B. ochracea Hepp Flecht. Europ. n. 263
(1851).
L. fuscorubens was considered by Nylander as possibly a variety or
subspecies of L. sanguineotra (Lich. Env. Paris, 79). It differs in the
absence of the purple hymeuial granules and in other characters.
Th. Fries (Lich. Scand. 440) has rightly judged L. ochracea to be
synonymous. They differ only in the occasional yellowness of the
very thin thallus of the latter. As in other calcicolous lichens, the
thallus is not always visible, being evidently immersed in the rock
(L. ochracea f. ecrustacea Larb. in Leight. l. c.).
Exsicc. Larb. Lich. Hb. nos. 64, 137; Johns. n. 336.
Hab. On calcareous rocks and flints in maritime and upland districts.
-Distr. Common on oolitic rocks and Silurian limestone in W. England;
here and there in the British Isles probably overlooked.-Downs,
Lewes and Hastings, Sussex; Portland, Dorset; Staple Fitzpaine,
Somerset; near Cheltenham, Gloucestershire; Epping Forest, Essex;
Dolgelly, Merioneth; Colwyn Bay, Denbigh; Kentmere, Levens Park
and Cunswick Scar, W Qstmorland; Barrowmouth, Cumberland; Ben
Lawers, Perthshire; Achosragan Hill, Appin, .Argyll; near Cork.
61. L. immersa Ach. Meth. 34 (1803).-Thallus effuse, very
thin, leprose, white or greyish-white, mostly immersed (K-,
CaCI -). Apothecia medium-sized, immersed in depressions or
pits (foveolate), plane, blackish, cresio-pruinose or naked, within
greyish in the middle, the margin thin, evanescent; paraphyses
concrete; epithecium and hypothecium more or less brownish;
spores ellipsoid or sub ellipsoid, 12-18 (.L long, 7-10 (.L thick;
hymenial gelatine bluish then wine-red with iodine.-S. F. Gray
Nat. Arr. i. 467; Hook. in Sm. Engl. Fl. v. 179; Tayl. in Mackay
Fl. Hib. ii. 125. L. calcivora Nyl. in Act. Soc. Linn. Bard. ser. 3,
i. 381 (1856); Mudd Man. 203; Cromb. Lich. Brit. 81; Leight.
Lich. Fl. 300; ed. 3, 310. lAchen immersus Web. Spicil. Fl.
Goett. 188 (1778) pro parte; Engl. Bot. t. 193; With. Arr. ed. 3,
iv. 6 pro parte. L. calm'l'orus Ehrh. Crypt. Exs. n. 244 (1793).
Exsicc. Bohl. n. 49 (plate); Leight. n. 94; Cromb. 11. 184.