PERTDSARIA.] LECANO-LECIDEEI. 497 



pulverulent, in convex, thinly margined, at length immarginate 

 verrucse (K + yellow, K(CaCl) + violet) ; spores 0,190-236 mm. 

 long, 0,050-070 mm. thick. Cromb. Grevillea, xix. p. 59. Vario- 

 laria amara Ach. Lich. Univ. (1810) p. 324 ; Hook. Fl. Scot. ii. 

 p. 46; Gray, Nat. Arr. i. p. 491. Lichen fayineus Linn. Huds. Fl. 

 Angl. p. 443 ? ; Lightf. Fl. Scot. ii. p. 807 ? ; With. Arr. ed. 3, iv. p. 4 

 pro parte ; Eng. Bot. t. 1713. Variolaria faginea Turn. & Borr. 

 Lich. Br. p. 64 ; Sm. Eng. Fl. v. p. 169 (uon Tayl. in Mack. Fl. 

 Hib. ii. p. 112). Pertusaria faginea Leight Lich. Fl. p. 242, ed. 3, 

 p. 232. Lichenoides candidum et farinaceum, scutellis fere plants 

 Dill. Muse. 131, t. xviii. f. 11 C. As Lichen fagineus of the older 

 authors is for the greater part a " nomen vagum," the determinate 

 and very expressive trivial name of Acharius is here adopted. 

 Brit. Exs. : Mudd, n. 263 pro parte. 



As noticed by Acharius (I. c.) the taste of the whole lichen is very 

 bitter, almost as in Cinchona. It has at times been confounded with the 

 discoid state of P. globulifera, but the taste, the chemical reactions, and 

 the smaller verrucse keep it distinct. The soredia are very numerous, 

 confluent, frequently almost obliterating the thallus except towards the 

 circumference. In Britain, as elsewhere, the apothecia are very rare in a 

 well-developed condition. 



Hub. On trunks of old trees, chiefly beech and elms, occasionally ash, 

 in maritime and upland wooded tracts.- Distr. General and not un- 

 common in Britain ; apparently rare in S.W. Ireland ; not seen from the 

 Channel Islands. B. M. : Great Glenham, Suffolk ; Hainault Forest and 

 near Gosfield, Essex ; St. Leonard's Forest, Sussex ; New Forest, Hants; 

 Lydford, S. Devon ; Withiel and near Penzance, Cornwall ; Minsty, 

 Wiltshire; CwmBychan, Merionethshire; Island of Anglesea ; Teesdale, 

 Durham ; Windermere, Westmoreland ; Asby, Cumberland ; Meldon 

 Park, Northumberland. Near Glasgow, Lanarkshire ; Craigforth, Stir- 

 ling ; Airds, Appin, Argyleshire ; Finlarig, Killin, Perthshire ; Craig 

 Cluny, Braemar, Aberdeensbire ; Applecross, Ross-shire. Dunkerron, 

 co. Kerry. 



10. P. velata Nyl. Lich. Scand. (1861) p. 179. Thallus deter- 

 minate, smoothish or rugoso-unequal, rimulose, obsoletely radiato- 

 rugose or plicate towards the circumference, whitish or milk-white 

 (K , CaCl-fred). Apothecia submoderate, plane, lecanoroid, pale 

 or white-suffused, thinly veiled, in small, depressed, concolorous 

 verrucas ; spores very large, 0,214-310 mm. long, 0,067090 mm. 

 thick, or occasionally somewhat smaller. Mudd, Man. p. 274; 

 Cromb. Lich. Brit. p. 59 ; Leight. Lich. Fl. p. 241, et ed. 3, p. 232 

 pro parte. Variolaria velata Gray, Nat. Arr. i. p. 490; Sm. Eng. 

 Fl. v. p. IW.Parmelia velata Turn. Trans. Linn. Soc. ix. (1808) 

 p. 143, t. 12. f. 1. Lichen velatus Eng. Bot. t. 2062. 



Might readily be taken for a state of Lecanora parella, but is at once 

 distinguished by the veiled apothecia and the thalline reaction with CaCl 

 From Pertusaria multipuncta, which it more distantly resembles, it 

 similarly differs in the reaction, as also in the form of the apothecia and 

 the larger spores. The fertile verruca? are occasionally very numerous 

 and crowded. 



2K 



