LECANORA,] LECANO-LECIDEEI. 39o 



furaceous on the surface. Apothecia minute, scattered ; spores 

 0,010-18 mm. long, 0,00G-8 mm. thick. — Forma 7iitlan;/ica Leight. 

 Lich. n. od. 3, p. 21-4. lUnodina lijjrosa * malawjica !Norm. ISf*ec. 

 loc. (18G8) p. 103. 



A very distinct varii'ty, or probably subspecies, differing in the cha- 

 racters given of tiio tliallus and apothecia. As observed by Th. M. Fries 

 (Lich. Sc-aud. p. :?01), it is very dissimilar iu habit to the type, but transi- 

 tion-states are not wanting. 



Hah. On trunks of old trees in an upland tract. — Distr. Only sparingly 

 iu W. England. — 13. M. : llaughmond lliU, Shropshire. 



Subsp. L. laevigata Xyl. ex Stiz. St. Gall. Xat. Ges, (1882) 

 p. 358. — Thallus effuse, thin, scattered, or scarcely anj- visible. 

 Apothecia rather small, usually lecideoid ; spores 0,014-20 mm. 

 long, 0,007-10 mm. thick. — Cromb. Grevillea, xviii. p, 46.— Z. 

 sophodes ft. hiviijuta Ach. Lich. L^niv. (1810) p. 357; Cromb. Lich. 

 Brit. p. 49; form lavirjata Leight. Lich. Fl. ed. 3, p. 215. 



Characterized by the little developed thallus, the type of the smaller 

 apothecia, and the thicker spores. The thallus is often evanescent when 

 the apothecia at length appear as if sublecideine (var. lecUJeiiui Nyl. oliiU; 

 in Herb. Mus. Feuu. p. 87). This is the ordinary condition of the plant 

 iu this country, where it does not, as elsewhere, occur corticolous. 



Hub. On rocks and walls in maritime and upland situations. — Didr. 

 Only sparingly iu a few localities iu Great Britain and Ireland. — B. M. : 

 Cirencester, Gloucestershire. Island of Lisiiiore, Argyleshire ; Craig 

 Guie, Braenuir, Aberdeenshire. Carrigaloe, co. Cork; Lettermore, Cou- 

 uemara, co. Galway. 



61. L. exigua Xyl. Flora, 1873, p. 197.— ThaUus subeffuse, thin, 

 unecjual, subgraiiulate or scattered, whitish, pale-greyish or dark 

 (K — ,CaCl— ); hypothaUus indistinct. Apothecia small, plane or 

 convex, crowded, black or blackish ; the thalline margin thin, often 

 somewhat crenulate, whitish ; hypothecium colourless ; spores 

 0,011-18 mm. long, 0,006-8 mm. thick. — Cromb. Grevillea, xviii. 

 p. 46 ; Sm. Eng Fl. v. p. 187. — Rinodina exigua Gray, Xat. Arr. 

 i. p. 450 ; Mudd, Alan. p. 143 pro parte. Lecanora sopJwdes var. 

 exigua Cromb. Lich. Brit. p. 49 ; form exigua Leight. Lich. Fl. 

 p. 224, ed. 3, p. 214. Lichen exlgims Ach. Prodr. (1798) p. 69 ; 

 Eng. Bot. t. 1849. Lichen pericleus (non Ach.) Eng. Bot. t. 1850. 

 Lecanora i^ericlea Sm. Eng. Fl. v. p. 187 : Tayl. in Mack. Fl. Hib. 

 ii. p. 133. liiiiodina ^^^I'i^'^ea Gray, Xat. Arr. i. p. 449 pro parte. 

 R. exir/iia S. periclca Mudd, Man. p. 143. — Brit. Exs. ; Mudd. n. 

 107; Larb. Lich. Hb. uos. 169, 261. 



Probably descends from L. sophodes. with which at times it seems sub- 

 contluent, but ditiers in the colour of the more effuse thaUus, and especi- 

 ally in the smaller spores. It usually spreads extensively, but at times 

 when associated with other crustaceous licheus it is much smaller, though 

 scai'cely limited bv a distinct hypothallus. It is always well fertile. 



