510 LICHENAOEI. [PERTESARIA. 



Form hexaspora Nyl. Lich. Scand. (1861) p. 182. Spores 

 usually 6nae, 0,038-86 mm. long, 0,025-38 mm. thick. Otherwise 

 as in the type. 



Differs merely in the thecae being generally 6-spored, though in the 

 same apothecium they are occasionally 4-spored. Nylander (/. c.) says 

 the spores are rarely 3nae, which is not the case in our specimens. 



Hob. On trunks of trees in maritime and upland wooded situations. 

 Distr. Only a few localities in S. and W. England. B. M. : Shanklin, 

 Isle of Wight ; near Lyndhurst, New Forest, Hants ; Ullacombe, Bovey 

 Tracey, S. Devon ; Oakley Park, Cirencester, Gloucestershire. 



29. P. glomerata Schaer. Spicil. (1823) p. 66. ThaUus effuse, 

 thin, interruptedly plicato-verrucose, white or yellow-cream-coloured, 

 the fertile verrucae subglobose, conglomerate (K-f- bright yellow, 

 then cinnabar-red, CaCl ). Apothecia usually solitary, the ostioles 

 punctiform or slightly dilated, generally somewhat prominent, 

 blackish; spores 0,072-125 mm. long, 0,028-44 mm. thick. 

 Hudd, Man. p. 277; Cromb. Lich. Brit. p. 60; Leight. Lich. Fl. 

 p. 237. ed. 3, p. 227. Lichen glomeratus Schleich. PI. Crypt. Cent, 

 iii. (1807) n. 11, fide Ach. Lich. Univ. p. 310 (sub Porina). Per- 

 tusaria fflomulifera (Borr.) Leight. Lich. Fl. p. 243, ed. 3, p. 234, 

 Angio. Lich. p. 30, 1. 11. f. 2, is only an old dealbate state in which 

 the reaction with K is absent. 



An alpine plant well distinguished from its allies by the characters 

 given and by the habitat. The thallus, scarcely contiguous, is itself 

 white (K-), as noted by Th. M. Fries (Lich. Scand. p. 315) ; but the 

 fertile verrucae, which are occasionally 2-3 concrescent, are more or less 

 ochroleucous. The few British specimens are well fertile, the ostioles 

 being at times two and often subpapillate. The spermogones, rarely 

 present, have the spermatia aciculari-fusiform, 0,008-11 mm. long, 

 0,0005 mm. thick (fide Nyl.). 



Sab. Incrusting dead mosses at high altitudes on mountains. Distr. 

 Local and scarce on the S. Grampians, Scotland. B. M. : Craig Calliach 

 and Ben Lawers, Perthshire. 



30. P. xanthostoma Fr. Lich. Eur. (1831) p. 427. Thallus 

 effuse, thin, smooth, milk-white, the fertile verrucae elevated, 

 depresso-subglobose (K , CaCl ). Apothecia punctiform, usually 

 1-2 in each verruca ; the ostioles depressed, pale or pale-yellowish ; 

 spores ellipsoid or ellipsoideo-oblong, 0,060-76 mm. long, 0,03440 

 mm. thick. Cromb. Journ. Bot. 1875, p. 141 ; Leight. Lich. Fl. 

 ed. 3, p. 235. Porina xanthostoma Somm. in Vet. Ak. Handl. 

 1823, p. 115. 



Has at first sight a considerable resemblance to Lecanora poriniformis 

 Nyl. The verrucse sometimes occur 2-3 together, and the ostioles are 

 occasionally tinged pale-reddish. Rarely 1-5 apothecia are seen hi 

 each verruca. 



Hob. On old stems of Ericas in alpine and subalpine localities. Distr. 

 Sparingly on the N. Grampians and in the N. Highlands of Scotland. 

 B. M. : Morrone, Braemar, Abardeenshire ; near Lairg, Sutherlandshire. 



