498 LICHEXACEI. [PERTUSARIA. 



Hab. On trunks and branches of trees in wooded upland tracts. Distr. 

 Very sparingly in S. England, N. Wales, and S. Ireland. B. M. : St. 

 Leonard's Forest, Sussex ; near Rusthall Common, Kent ; Quarn Wood, 

 Isle of Wight ; New Forest, Hants ; East Lulworth, Dorsetshire ; Ivy 

 Bridge, S. Devon ; Island of Anglesea. Castlemartyr, co. Cork. 



Form aspergilla Cromb. Grevillea, xix. (1891) p. 59. Fertile 

 verrucse scattered, elevated, scarcely margined, white-pulverulent ; 

 otherwise as in the type. Variolaria aspergilla Turn. & Borr. Lich. 

 Br. p. 67 ; Sm. Eng. Fl. v. p. 170 ; Eng. Dot. t. 2401 ; Tayl. in 

 Mack. Fl. Hib. ii. p. 1.12. V. communis var. y. asperc/illa Gray, 

 Nat. Arr. i. p. 491. Lichen asperyillus Ach. Prodr. (1798) p. 28 ? 



Differs in the character of the verrucse ; while in the British specimens 

 seen the thallus is also thinner. Our plant, which is that of Turner and 

 Borrer pro maxima parte, may be different from that of Acharius and 

 other authors, who speak of it as only saxicolous. 



Hab. On trunks of trees and pales in upland situations. Distr. Only a 

 few localities in S. and Central England. B. M. : Ickworth, Suffolk ; 

 Sevenoaks, Kent ; St. Leonard's Forest, Sussex ; Shiere, Surrey ; .New 

 Forest, Hants ; Gopsall Park, Leicestershire ; Hay Park, Herefordshire. 



11. P. reducta Stirfc. Scottish Naturalist, iv. (1877) p. 28. 

 Thallus thin,rimuloso-areolate, greyish or greyish-brown (K + yellow, 

 then deep red). Apothecia sessile, lecanorine, inclosed in mono- 

 carpous thalline verruca?, brown or reddish-brown, caesio-pruinose ; 

 spores 0,09-14 mm. long, 0,03-04 mm. thick. Leight. Lich. Fl. 

 ed. 3, p. 229. 



The author says 1. c. that it is " closely allied to P. multipuncta ; " but 

 from this it is widely separated by the type of the apothecia and the 

 thalline reaction. I have seen no specimen. 



Hab. On trees in a mountainous region. Distr. Local and rare in the 

 S.W. Highlands of Scotland (Ben Brecht, Argyleshire) . 



12. P. lactea Nyl. Flora, 1881, p. 539. Thallus determinate, 

 smooth, rimoso-areolate, subeffigurate at the circumference, greyish 

 or whitish (K , CaCl + reddish). Apothecia lecanorine, small, 

 scattered, white, subleprose above, the thalline margin irregular ; 

 spores 0,0180-205 mm. long, 0,063-70 mm. thick. Crorab. Gre- 

 villea, xix. p. 59. Variolaria lactea Gray, Nat. Arr. i. p. 492; 

 Hook. Fl. Scot. ii. p. 46 ; Turn. & Borr. Lich. Br. p. 62 ; Sm. Eng. 

 Fl. v. p. 170 ; Tayl. in Mack. Fl. Hib. ii. p. 113. Pertusaria lac- 

 tescens ft. lactea Mudd, Man. p. 272. Lichen lacteus Linn. Mant. 

 (1767) p. 132; Huds. Fl. Angl. ed. 2, p. 526; With. Arr. ed. 3, iv. 

 p. 5 ; Eng. Bot, t, 2410. 



A plant whose systematic place was doubtful till the recent discovery 

 of the fructification, which renders it a very well-marked species. The 

 thallus, though orbicular, usually spreads very extensively over the sub- 

 stratum, varying somewhat in thickness, the sterile verrucas being at 

 times numerous and subcontinent in the areolae. With us it is very 

 rarely fertile. 



