rnrsciA.] rnYsciEi, 317 



columnoris Tayl. in Fl. Hib. ii. p. 144, is a more granulose state. — 

 Brit. Exs.: Lciglit. n. 324. 



Easily reco<rnizt'd by the tliallus being often almost entirely granulose 

 or leprose, with the laciniai visible only at or towards the circumference. 

 With us it is but seldom and sparingly seen with apothecia. The sper- 

 mogones apparently do not occur in Britain. 



Jlab. On the trunks of trees, often in orchards, and on tiled roofs in 

 maritime and lowland districts. — Distr. Somewhat local and scarce in 

 S. and Central ]<]ngland, N. Wales, S. Ireland, and the Ciiannel Islands ; 

 not seen from Scotland. — B. ]M. : St. Martin's, Island of .Jersi'V ; Island of 

 Guernsey. Epping Forest, Essex ; near Maidstone and Tunbrilgo Wells, 

 Kent; near Lewes, between Ileutield and Brighton, and IIur>ipiL-r; uint, 

 Sussex; near Southampton, Hants ; Hyde, Isle of Wight; near Plyninutli, 

 Devonshire ; Penzance, Cornwall ; West Haddon, Xorihamptonshire ; 

 near Barmouth, Merionethshire. Tervoe, co. Limerick ; Carrigalim, near 

 Cork. 



Form elegans Xyl. ex Leight. Lich. FL cd. 3 (1879) p. 139.— 

 ThaUus glaucous-white ; lacinite finely isidioso-fimbriate at the mar- 

 gins. Apothecia not seen. — Brit. Exs. : Larb. Lich. Hb. n. 88. 



The peculiar fimbriate margins of the laciniae, which are not leproso- 

 granulose, render this a somewhat distinct form. It does not occur 

 fertile. 



Hab. On rocks in a maritime district. — Distr. Found only veiT 

 sparingly in N. W. Ireland. — B. M. : Kj-lemore Lake, co. Galway. 



20. P. caesia Xyl. Act. Soc. Linn, liord. ser. 3, i. (1856) p. 308. 

 ^Tballus orbicular, closely adnate, stellate, miiltifido-laciniate, 

 osesio-wbite or greyish-white, sprinkled with csesious subglobose 

 5oredia ; beneath pale and sparingly fibrillose ; laciniae narrow, con- 

 rex, contiguous, slightly dilated at the apices (Ki^yellow, CaCl~). 

 Apothecia sessile, small, concave or plane, black, naked or pruinose, 

 the thalline margin thickish, entire or crenulate ; spores oblong, 

 0,016-23 mm. long, 0,009-13 mm. thick.— Cromb. Lich. Brit. p. 39. 

 -^Physcia steUaris var. ccesia Leight. Lich. Fl. p. 152, ed. 3, p. 141. 

 Borrera casia Mudd, Man. p. 107. Sqiiamaria ccesia Sm. Eng. Fl. 

 V. p. 196. Parmelia ccesia Gray, Xat. Arr. i. p. 443 ; Tayl. in Mack. 

 Fl. Hib. ii. p. 147. Lichen ccesivs Hoffm. Enum. (1784) p. Qb, 

 t. J 2. f. 1 : Eng. Bot. t. lo52. Lichen Psora Dicks. Ciypt. fasc. iii. 

 p. 17; With. AiT. ed. 3, iv. p. 26. Lichenoides cinereum, sec/mentis 

 artjutis stellaiis, scutellis nigris Dill. Mnsc. 176, t. 24. f. 70 c. — Brit. 

 Exs. : Leight. n. 323. 



Distinguished from its more immediate allies by the puhinate csesious 

 soredia, which are scattered regularly over the thallus and rarely become 

 confluent. The apothecia are chiefly central and not of frequent occur- 

 rence. 



Hah. On walls, roofs, and boulders in lowland and upland districts. — 

 Distr. Generd though not common in England ; much rarer in Scot- 



