EVERXIA.] PARMELIEI. 231 



Sp. PI. (1753) p. 1146 ; Huds. Fl. Angl. p. 450 ; Ligtitf. Fl. Scot. ii. 

 p. 832 ; With. Arr. ed. 3, iv. p. 56. Lichenoides cornutum amarum, 

 superne cinereum, in/erne nigrum Dill. Muse. 157, t. 21. f. 52. Brit. 

 Exs. : Leight. n. 37 ; Mudd, n. 40. 



The furfur with which the thallus is usually covered above, and the 

 different colours of the upper and the lower surfaces, readily prevent this 

 being confounded with E. prunastri. Occasionally, when growing on the 

 tops of stone walls, it is somewhat orbicular, depressed, and loosely 

 adnate, with a very few obscure rhizinse towards the point of attachment. 

 The variations in the laciniae give rise to the several forms described 

 below. The apothecia, which at length become plane and large, are 

 rarely seen in Britain. The spermogones and spermatia are as in the 

 preceding species. 



Hub. On the trunks of trees, old pales, walls, and sometimes rocks, in 

 upland districts. Distr. General and not uncommon in the mountainous 

 tracts of Great Britain ; most frequent in the Central Highlands of Scot- 

 land ; apparently very local in Ireland. B. M. : New Forest, Hants ; 

 Dartmoor and South Brent, Devonshire ; Helminton, Cornwall ; Chester- 

 tield, Darley, and near Buxtoii, Derbyshire ; near Oswestry, Caer Caradoc, 

 and Wrekin Hill, Shropshire ; Cwm Bychau, Merionethshire ; Island of 

 Anglesea ; Arkindale and Farndale, Yorkshire ; Eglestone, Durham ; 

 Kentmere, near Kendal, Westmoreland ; Chilliugham Park, Northumber- 

 land. New Galloway, Kirkcudbrightshire ; Swanston Wood, near Edin- 

 burgh ; Gleni'alloch, Argyleshire ; Blaeberry Hill, Glen Lochay, Killin, 

 and Glen Lyon, Perthshire ; Deerhill Wood and Johnston Hill, Forfar- 

 shire; Invercauld, Auchindryiie, and Castleton, Braemar ; Glen Nevis, 

 Inverness-shire. Lough Bray, near Dublin. 



Form 1. nuda Cromb. Grevillea, xv. (1887) p. 74. Thallus 

 smaller ; lacinise shorter, broader, somewhat plane, pale or here and 

 there subviolet, naked. Borrera furfuracea ft. nuda Ach. Lich. Univ. 

 (1810) p. 500. 



A smalltr plant, with the thallus entirely glabrous and the laciniae 

 broader. The apothecia are not present in our specimens. 



Hob. On old pales and the trunks of birches in upland situations. 

 Distr. Found only sparingly in the S. W. Highlands and the N. Grampians, 

 Scotland. B.M. : Crianlarich, Perthshire ; Morrone, Braemar, Aberdeen- 

 shire. 



Form 2. scobicina Nyl. Lich. Scand. (1861) p. 73. Laciniae 

 broader, densely isidioso-furfuraceous or isiclioso-fibrillose ; other- 

 wise as in the type. Cromb. Lich. Brit. p. 24 ; Leight. Lich. Fl. 

 p. 90. Parmelia furfuracea y. scobicina Ach. Meth. (1803) p. 255. 



Differs chiefly in being crowdedly isidiiferous ; the thallus is usually 

 dark greyish, and the laciniae less branched, broader and lacero-laciniate 

 towards the apices. It is rarely fertile ; the apothecia occasionally have 

 both the margin and the back of the receptacle minutely isidiose. 



Hob. On the trunks of trees, old pales, and stone walls in upland 

 districts. Distr. Rather local, though plentiful in W. and Central 

 England ; but chiefly in the Grampians, Scotland. B. M. : Gopsall, 

 Park, Leicestershire ; Malveru, AVorcestershire. Killin and Ben Lawers, 

 Perthshire; Castleton of Braemar, Aberdeenshire ; llothieniurchus, 

 Inverness-shire. 



