verrucaria] verrucariace^ 293 



Thallus tartareous, thin ; perithecia forming pits in the rocks. 



39. V. rupestris Schrad. Spicil. p. 109 (1794) pro parte; 

 DC. Fl. Franc, ii. p. 317 (1805).— Thallus white or greyish-white 

 or brownish, effuse, thin, tartareous, pulverulent. Perithecia 

 moderate in size, black, numerous, hemispherical, semi-immersed, 

 leaving shallow pits in the stone ; perithecial wall dimidiate, a 

 thin brown wall passing under the base ; spores ellipsoid-oblong, 

 0,018-30 mm. long, 0,008-013 mm. thick.— Hook, in Sm. Engl. 

 Fl. V. p. 152 ; Tayl. in Mackay Fl. Hib. ii. p. 90; Mudd Man. 

 p. 291 ; Cromb. Lich. Brit. p. 114 (excl. vars.) ; Leight. Lich. Fl. 

 p. 425 ; ed. 3, p. 456 (excl. vars.). 



Nearly allied to the following species but with smaller dimidiate 

 perithecia, which are somewhat prominent and leave very shallow pits 

 when they drop out at maturity. 



Hah. On stones and rocks, chiefly calcareous. — Distr. Frequent 

 throughout the British Islands. — B. M. Torquay, Devonshire ; 

 Rottingdean and Newhaven, Sussex ; Sapperton, Gloucestershire ; 

 Twycross, Leicestershire ; Trefriw, Carnarvonshire ; Appin, Argyll ; 

 Middleton, Cork. 



Var. subalbicans Mudd Man. p. 292 (1821).— Thallus 

 greyish-white, thin, pulverulent. Perithecia slightly larger than 

 in the species and with a more developed wall below the base, 

 leaving scarcely perceptible pits in the substratum ; spores as in 

 the species. — Leight. Lich. Fl. p. 426 ; ed. 3, p. 457. V. sub- 

 albicans Leight. Angioc. Lich. p. 56, t. 25, fig. 1 (1851). 



Exsicc. Leight. no. 200. 



Difficult to distinguish from V, Integra except in the persistently 

 smaller spores. 



Hab. On mortar, plastered walls, &c. — Distr. Rather rare in 

 S. and N. England and N.W. Wales. — B. M. Near Ayton, Cleveland, 

 Yorkshire ; Bangor, Carnarvonshire. 



40. V. Integra Carroll in Journ. Bot. iv. p. 25 (1866). — 

 Thallus white or greyish-white, subcrustaceous, tartareous, sub- 

 farinose. Perithecia black, numerous, moderate in size, semi- 

 immersed, leaving shallow pits in the rock, hemispherical, de- 

 pressed above ; perithecial wall thick, black, somewhat spreading 

 at the base with a thinner black wall beneath the base ; spores 

 ellipsoid-oblong, rather large, 0,023-32 mm. long, 0,010-20 mm. 

 thick. — Leight. Lich. Fl. p. 426 ; ed. 3, p. 457. V. rupestris var. 

 integra Nyl. in Act. Soc. Linn. Bord. ser. 3, i. p. 429 (1856) ; 

 subsp. integra Nyl. Lich. Scand. p. 276(1861); Cromb. Lich. 

 Brit. p. 114. Sagedia ampullacea Deakin in Ann. Mag. Nat. 

 Hist. ser. 2, xiii. p. 39, t. 4, tig. 11 (1854)? 



Differs from V. rupestris in the entire perithecial wall and the 

 somewhat large perithecia and spores. 



Hab. On rocks, mostly calcareous, mortar, &c. — Distr. Rather 

 rare in S., Central and N. England, among the Scottish Grampians 



