LECANORA. | LECANO-LECIDEEI. 381 
Hab. On the smooth bark of ash and poplars in maritime and upland 
districts. — Distr. Sparingly in S.and W. England, and among the Central 
Grampians, Scotland—B. M.: Shanklin, Isle of Wight; New Forest, 
Hants; Withiel, Cornwall. Craig Tulloch, Blair Athole, Perthshire. 
Form 2. albiseda Nyl. Lich. Scand. (1861) p. 144.—Thallus 
very thin, white. Apothecia bright-yellow, the thalline margin 
thin, white.— Cromb. Grevillea, xviii. p. 46. 
A peculiar form, differing in the colours of the thallus, the apothecia, 
and their thalline margin. 
Hab. On old pales in upland districts.—Distr. Only very sparingly 
in §. England and S.W. Ireland.—B. M.: near Lewes, Sussex. Dun- 
kerron, co. Kerry. 
Var. 6. stillicidiorum Nyl. Mém. Soc. Cherb. t. v. (1857) p. 112; 
Lich. Scand. p. 144.—Thallus effuse, very thin, granulose or 
leprose, greyish-white; hypothallus obsolete. Apothecia small, 
yellowish- or olive-green, or dark olive, pruinose, the thalline 
margin undulate, pale-greyish.—Cromb. Lich. Brit. p. 47 ; Leight. 
Lich. Fl. p. 221, ed. 3, p. 210.— Callopisma cerinum y. stillicidiorum 
Mudd, Man. p. 186. Rinodina stillicidiorwm Gray, Nat. Arr. i. 
p. 456. Lrehen stillicidiorum Hornem. Fl. Dan. (1792) t. 1063. 
f.2. Lecanora chloroleuca Hook. Fl. Scot. ii. p. 48; Sm. Eng. Fl. 
v. p. 190. Lichen chloroleucus Sm. Eng. Bot. t. 1873.— Brit. Evs. : 
Bohl. n. 94. 
Probably rather a subspecies (cf. Norrl. Medd. Sillsk. pro F. & Fl. 
Fenn, i. p. 22), differing in the absence of a hypothallus, the colour of 
the fructification, and in the habitat. The thallus spreads rather exten- 
sively and the apothecia are numerous, with the thalline margin rarely 
subpulverulent. 
Hab. Tncrusting masses, on calcareous rocks, in upland and subalpine 
situations.—Distr. Local, though not uncommon where it occurs in 
8.W., Central, and N. England, N. Wales, the 8.W. Highlands and among 
the Grampians, Scotland; not seen from Ireland.—B. M.: Dartmoor, 
Devonshire ; near Buxton, Derbyshire ; Dolgelly, Merionethshire; Egle- 
stone, Durham; Cunswick Scar, Westmoreland; near Skelton, Cumberland. 
Achrosagan Hill, Appin, Argyleshire ; Craig Tulloch, Perthshire; Craig 
Guie and Morrone, Braemar, Aberdeenshire. 
Subsp. 1. L. chlorina Nyl. ea Lamy, Bull. Soc. Bot. t. xxv. 
(1878) p. 505.—Thallus effuse, thickish, granuloso-verruculose or 
areolato-rimulose, verdigris- or dark-green; hypothallus not dis- 
tinct. Apothecia darker cerine.—Cromb. Grevillea, xviii. p. 46.— 
Lecanora cerina var. chlorina Leight. Lich. Fl. p. 221, ed. 3, p. 210. 
Callopisma cerinum 3. chlorinum Mudd, Man. p. 186. Zeora cerina 
var. chlorina Flot. Lich. Siles. (1849) p. 216.—Brit. Hxs.: Larb. 
Lich. Hb. n. 22. 
Distinguished as a subspecies by the more developed thallus, its very 
different colour, and by the darker apothecia. The hypothallus is con- 
fused with the thallus. In the few British specimens the apothecia are 
