272 LICHENACEl. [t'OBARIA. 



renm maximum Dill, in Ray Syn. ed. 3, p. 76, n. 86. Brit. EPS. : 

 Leight. n. 74; Mudd, n. 64 ; Cromb. n. 37. 



The familiar " Tree Lungwort," when fully developed, is one of the 

 largest, as it is one of the most common, of the British species of this 

 tribe. It varies considerably in the breadth and divisions of the lobes, 

 old plants being much broader and less laciniate. The thallus, which 

 hangs loosely from the trunks on which it grows, is more or less shining, 

 especially in young plants, while the lacinise are often whitish aorediato 

 and isidiate at the margins. Usually also seriately arranged soredia and 

 occasionally isidia are present in the' costae between the faveolse. States 

 in which the isidia are numerous and crowded fonn the variety papittaris 

 Del. Stict. p. 144, t. 17. f. 03. "\Vith us it is comparatively rare in a 

 fertile condition, though the apothecia are sometimes very numerous. 



Hob. On the trunks of forest trees, especially old oaks, in mountainous 

 regions, rarely on mossy rocks in maritime districts. Dixtr. General and 

 for the most part plentiful in the Channel Islands, the more Western 

 tracts of Great Britain, and probably of Ireland ; fruiting more freely in 

 the S.W. Highlands of Scotland. B. M. : Boulay Bay, Island of Jersey; 

 Island of Guernsey. Near Loughton, Essex ; near Lydd, Kent ; Hyde 

 and Appuldurcomb, Isle of Wight ; New Forest, Hants ; Lydford, Tot- 

 nes, Buckfastleigh, and Ivv Bridge, Devonshire ; Bocounoc, Pentire, St. 

 Minver, and near Penzance, Cornwall ; Bryer Island, Scilly ; Chedworth 

 Woods, near Cirencester, Gloucestershire ; Bagley Wood, near Oxford ; 

 Charnwood Forest, Leicestershire ; near Ludlow, Shropshire. Cader 

 Idris, Rhewgreidden, Aberdovey, and Barmouth, Merionethshire : near 

 Dolgelly, Bettws-v-Coed, Denbighshire ; Conway and Devil's Bridge, 

 Carnarvonshire ; Beaumaris, Island of Anglesea ; Kildale, Cleveland, 

 Yorkshire ; Eglestone and Teesdale, Durham ; near Grasamere, West- 

 moreland ; Cheviots, Northumberland ; Patterdale and Gaidar Abbev, 

 Cumberland. New Galloway, Kirkcudbrightshire ; near Moffat, Dum- 

 friesshire ; Pentland Hills and Turh'n Hill, near Edinburgh ; Inverarv, head 

 of Loch Awe, Barcaldine, and Appin, Argyleshire ; The Trossachs, Loch 

 Katrine, and Killin, Perthshire ; Reeky Linn, Lundie Craigs, and Clova, 

 Fort'arshire ; Dunottar Castle, Kincardineshire ; Craig Cluny and Cor- 

 riemulzie, Braemar, Aberdeenshire ; S. of Fort William, Inverness-shire ; 

 Applecross, Ross- shire. Dinish and Ronayne's Island, Killarney, co. 

 Kerry ; Lough Inagh, co. Galway. 



Var. pleurocarpa Ach. Lich. Univ. p. 450 (Cromb. Exs. n. 137), is a 

 state in which the apothecia are abortive, tuberculoso-difform and brown- 

 ish-black in consequence of being the host of Celidium stictarutn, Tul. 

 In the Museum herbarium there are specimens showing this condition 

 from the following localities : Bocconoc, Cornwall ; Haf od, Cardigan- 

 shire; Cwn Bychan, Merioneth. Appin and head of Loch Awe, Argyle- 

 shire ; The Trossachs, Perthshire ; Cawdor Woods, Nairn. 



Form 1. hypomela Cromb. Grevillea, xv. (1887) p. 76. Thallns 

 with the interstices of the under surface reticulate with black rhi- 

 zinae. Apothecia with the thalline margin rugoso-crenulate. Sticta 

 ptilmonacea var. hypomela Del. Stict. (1825) p. 144, t. 17. f. 64; 

 Nyl. Syn. i. p. 352. Brit. Exs. : Cromb. 11. 136. 



Approaches L.&etiffera (Ach.), an exotic species, in the character of the 

 thallus beneath, which probably results from the habitat, the type itself 

 at times having the rhizinae dark brown. With us it is seldom well 

 fruited. 



