rvRMIJ.n.J PAKMKLIF.r. 211 



ontire or crcnul.ite ; spores 0,014-1!) mm. lon», 0,000-12 imn. 

 tliick. — (Jrav, Xat. Arr. i. p. 410 : Hook. Fl. Scot. ii. p. 'y.i ■ Siu. 

 Knj?. Fi. V." p. 100; Tayl. in M:ick. Fl. Hib. ii. p. 144; Mudd, 

 Mail. p. 94; Cromb. Lich. Brit. p. .'U ; Leight. Lich. Fl. p. V.iT, 

 o(l. .'J, p. 120. — Lichen saxadli^ Lirm. Sp. PI. (1753) p. 1142; 

 Hiids. Fl. An.?!, p. .>J1; Lightf. Fl. Scot. ii. p. 810; With. Arr. 

 ed. 3, iv. p. 33; Eiig. Bot. t. 003. Lichenoides vnlr/atissiinum 

 cinereo-ijhxHCiim Inciniosum el eirrhomim Dill. Muse. 118, t. 24. 

 f. s;3a. Lichenoides crusta foliosa, siiperne cinereo-qlauca, inferne 

 nii/ra et cirrhoxd, scxteUis nirfricanlUnis Dill, in llav, Syii. cd. 3, 

 p. 72, n. 10. — Under the type was included also the following form 

 by mos+; of our earlier authors. — Brit. Rvs. : Leight. n. 203 pro 

 parte ; Cromb. n. 27. 



This well-known species is readily recognized by the reticulato-rugu- 

 lost> tliallus. Often very widely spreading, it is one of the largest plants 

 of the genus, and thouurh sinietinies subsmuoth is usually i.<idioso-scabrid 

 oil the rugne. It is seldom feitilf, the apothecia, which are at tirst urceo- 

 late and moderate, becoming at length large and flexuose. The sperniiv 

 gone*, which are not uneommon, are very minute, black, with spermatia 

 0,007 mm. long, ab >ut 0,001 mm. thick. The panisites Dothidea /wmosfet/ia 

 Nyl. and Ahri>thalluJ( parasiticus' Xyl. (Lichen parasiticus Sm. Eng. Bot. 

 t. 1860) are often met with on the thallus of this species and of the form 

 here described. 



Hah. On trees, walls, rocks, and boulders in upland and subalpine, 

 sometimes in lowland districts. — Distr. Local throughout Great Britain; 

 rare in the Channel Islands ; not .-een from Ireland. — B M. : Island of 

 Ouernsey. Near Brighton, Sussex ; Basing-tuke, Hampshire : near Pen- 

 zance, Cornwall; Malvern Hills, Worcestershire ; Wiekin Hill, Shrup- 

 shire; Lambeth, S. Wales; Island of Anglesea ; Siavely, Westmore- 

 land. Appin, Argyleshire ; Killin, Ben Lawers, Abernethy, Black Wood 

 of Rannuch. and Ben Vrackie, Perthshire; Cortachy. Forfarshire ; Por- 

 tlethen, Kincardineshire ; Corriemulzie, Braemar, Aberdeenshire ; Ben 

 Isevis, Inverness-shire. 



Form furfuracea Schoer. Spic. (1S40) p. 455. — Thallus much 

 expanded, greyish- white, densely covered with greyish-brown 

 isidia : otherwise as in the type. — Mudd, Man. p. 95 ; Leight. Lich. 

 Fl. p. 138, cd. 3, p. 127; Cromb. Linn. Soc. Joum. Bot. svii. 

 p. 573. — Pannelia horrescens Tayl. in Mack. Fl. Hib. ii. p. 144 

 pro parte. — Lichenoides vuJgatissimiun cinereo-qlaucura lactinostrm et 

 cirrhosum Dill. Muse. 188, t. 24. f. SSc, -D.—Brif. Rvs.: Leight. 

 n. 40 pro parte ; Larb. Lich. Hb. n, 211 ; Bohl. n. 11. 



Remarkable on account of the isidiose furfur with which it is frequently 

 covered and which obUterates the lobes except at the circumference, 

 giving it a panniform appearance. Smaller and .sterile states in this con- 

 dition, and some very sparingly isidiiferous, are the form pamiifonnis 

 ( Cromb. Grevillea, xv. p. 75). The thallus is often dark-grey, and occa- 

 .<;ionally becomes centrifugal from the decay of the central portions, when 

 it may present merely a narrow circumferential border. The apothecia, 

 which are frequent, have the thalUue margin sometimes exasperate with 

 the isidia. 



Hab. On rocks, walls, and trees, chiefly in upland districts. — Distr. 



R 



