470 LICHKNACEI. [lECANOEA. 



and occasionally bears pale-reddish cepbalodia similar to those of Zmr/ca 

 piiiKPiila. When o-rowing iu wet places by streams it is more expanded, 

 of a livid-grey colour, non-cephalndiiferous, with the thalline margin 

 of the apothecia usually obliterated (form rinilan't, Cromb.). The 

 apothecia are somewhat scattered, innate or at length nearly superficial, 

 with the disc free at the circumference. 



JIab. On micaceo-schistose roclcs in alpine places. — Distr. Only very 

 sparingly near the summits of two of the S. Grampians, Scotland. — 

 B. M. : Ben Lawers and Craig Calliach, Perthshire. 



169. L. gibbosa Xyl. Xot. Siillsk. pro F. et Fl. Fenu. Furh. n. s. 

 V. (1860) p. 137. — Thallus determinate, thick, areolato-verrucose 

 or gibbous, greyish, dark-grey or dark-greenish-brown (K — , 

 CaC'l — , medulla I—); hypothallus black, limiting the thallus. 

 Apothecia at first immersed and concave, then emersed and plane, 

 submoderate, black, naked; the thalline margin entire or slightly 

 crenulate, persistent ; spores 6-8nse, rarely 4nce, ellipsoid or sub- 

 globose, large, 0,021-33 mm. long, 0,012-24 mm. thick ; paraphyses 

 not discrete ; hyraenial gelatine pale-bluish, then tawny or sordid- 

 wine-red with iodine. — Leight. Lich. Fl. ed. 3. p. 193, ed. l,p. 209 

 pro iiarte ; Cromb. Lich. Brit. p. 55 pro parte. — AspiciUa gibbosa 

 Mudd, Man. p. 162. Urceolaria gibbosa Sra. Eng. Fl. v. p. 172; 

 Gray, Xat. Arr. i. p. 458. Lichen giUiosus Ach. Prodr. (1 798) p. 30. — 

 Liciien gibbosus Dicks. Crypt, fasc. ii. (1790) p. 20, t. vi. f. 5 ; "With. 

 Arr. ed. 3, p. 20, from the diagnosis and locality cited is evidently 

 not this species. — Brit.Exs. : Leight. n. 175 ; Cromb. n. 167 ; Larb. 

 Lich. Hb. n. 220. 



A very variable plant presenting the varieties and subspecies that 

 follow : while several states of the type itself were by older authors 

 regarded as distinct species. In a young condition, especially when 

 silicicolous, the predominating hypothallus, black and radiately sub- 

 plumose, is everywhere visible, the thalline verrucse being more or less 

 scattered. It is then Lichen fbroms Eng. Bot. t. 1739 ; Urceolaria 

 yibbosa var. 3. fmhriata Ach., Gray Nat. Arr. i. p. 4oS. The same with 

 the verrucas here and there greeuish-sorediiferous, owing no doubt to 

 habitat (moist flints), is Lecanora aspersa Borr. Eug. Bot. Suppl. t. 27:^8 ; 

 Sm. Eng. Fl. v. p. 188. Another state, in which the thalline verruca? are 

 subglobular and often discrete, is Lichen tulerctdosus Eng. Bot. t. 173.3 ; 

 Rinodina tuberculosa Gray Nat. Arr. i. p. 4o2 ; Lecanora tuberculosa Sm. 

 Eng. Fl. V. p. 183. Occasionally the thalline margin of the young 

 apothecia is coarctate or subcrenulate, whence forma porinoidea ( Flot. 

 Lich. Siles. i. p. 128) Leight. Lich. Fl. ed. 3, p. 194. All of these, how- 

 ever, where the plant is very abundant (as in the Kentish locality), 

 often pass into and are mixed up with each other in the same specimen. 

 The spermogones, especially in younger states of the plant, are very 

 fi-equent, with spermatia 0,009-0,012 mm. long, scarcely 0,001 mm. thick 

 {Jide Nyl. Lich. Pyr. Or. Obs. nov. p. o9). 



Kah. On rocks and stones (chiefly flints') in maritime and hilly 

 districts. — Di&tr. Local, though plentiful, in 8., W., andN. England ; rare 

 in Wales and in the S.W. Highlands of Scotland : not seen from Ireland 

 nor the Channel Islands. — B! M. : Ryde, Isle of Wight ; Lydd Beach, 

 Kent; Lewes, S. Downs, St. Leonard's, and Beachy Head, Sussex; 



