LECANORA.] LECANO-LECIDEEI. 387 



Hab. On vegetable detritus in maritime districts. Distr. Only very 

 sparingly in S. England and the S.W. Highlands of Scotland. B. M. : 

 Luccoinbe Cove, Isle of Wight ; Rottingdean Cliffs, Sussex. Airds, 

 Appin, Argyleshire. 



49. L. irrubata Nyl. ex Norrl. Medd. Siillsk. pro F. & Fl. Fenn. 

 i. (1876) p. 22. Thallus determinate, thin, rimose or rimoso- 

 areolate, sordid or greyish (K ). Apothccia adnate, small, biato- 

 rine, somewhat plane or convex, immarginate, yellow-reddish (K + 

 purplish); spores ellipsoid or ovoid, simple, 0,009-0,011 mm. long, 

 0,005-6 mm. thick. ; paraphyses scanty. Cromb. Grevillea, xii. 

 p. 58. Lecanora calva var. irrubata Cromb. Lich. Brit. p. 47. 

 Lecidea irrubata Sm. Eng. Fl. v. p. 183 ; Tayl. in Mack. Fl. Hib. 

 ii. p. 128. Lecanora rupestris forma viridi-Jiavescens (Wulf.) Leight. 

 Lich. Fl. p. 191, ed. 3, p. 204. Lecidea rupestris y. viridiflavescens 

 Mudd, Man. p. 194. Lichen rupestris Eng. Bot. t. 2245. Brit. 

 Exs.: Leight. n. 119 ; Mudd, n. 161; Larb. Lich. Hb. n. 100. 



Usually arranged by authors among the Lecideei owing to its simple 

 spores and biatorine apothecia. Its true place, however, is among other 

 biatoriue species of this section, as shown by the spermogones. From 

 the more developed thallus, which is usually limited, it is to be regarded 

 as the specific type rather than the subspecies that follows. The apo- 

 thecia are numerous, usually small, rarely submoderate. The spermo- 

 gones, which are externally black-punctate, have the spermatia cylindrical, 

 about 0,005-6 mm. long, 0,001 mm. thick. 



Hab. On calcareous rocks, siliceous and cretaceous stones, and the 

 mortar of walls in maritime and upland localities. Distr. Not uncommon 

 in England ; not seen from Wales ; apparently rare in Scotland and 

 Ireland. B. M. : Shiere, Surrey ; Beachy Head, Sussex ; Anstey's Cove, 

 Torquay, and Cornworthy, S. Devon ; near Penzance, Cornwall ; Bath- 

 ampton Downs, Somersetshire ; Windsor Great Park, Berks ; Norton, 

 near Worcester ; Whitecliffe Rocks, near Ludlow, Shropshire ; Bonsall, 

 Derbyshire ; Bilsdale and near Carlton, Cleveland, Yorkshire ; Beamish, 

 Durham ; Leven's Park, Westmoreland ; Chollerford, Northumberland. 

 Appin, Argyleshire ; Craig Tulloch, Blair Athole, Perthshire; Kirklnnd, 

 Fifeshire. Killarney, co. Kerry ; Ben Bulben, co. Sligo ; near Kylemore, 

 co. Galway. 



Subsp. L. calva Nyl. ex Lamy, Bull. Soc. Bot. t. xxx. (1883) 

 p. 379. Thallus effuse, very thin, whitish, or scarcely any. Apo- 

 thecia small or moderate, convex, vitelline or tawny-yellow ; spores 

 0,009-0,014 mm. long, 0,005-8 mm. thick ; paraphyses thick. 

 Cromb. Grevillea, xviii. p. 46. Lecanora calva Cromb. Lich. Brit, 

 p. 47. Lecanora rupestris form calva Leight. Lich. Fl. p. 191, ed. 3, 

 p. 203. Lichen calvus Dicks. Crypt, fasc. ii. (1790) p. 18, t. 6. f. 4 ; 

 With. Arr. ed. 3, iv. p. 14 ; Eng. Bot. t. 948. Lecidea rupestris 

 (? Scop.) Gray, Nat. Arr. i. p. 472 ; Sm. Eng. Fl. v. p. 183 ; Tayl. 

 in Mack. Fl. Hib. ii. p. 128 : Mudd, Man. p. 193. 



Often spreads extensively with the thallus indistinct, being confused 

 with the substratum. The apothecia are at times somewhat large, and 

 then more convex, immarginate and scattered. 



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