27:^ LiCHEXACEi. [lobabia. 



reum iiui.rhnv.in Dill, in Ray Syn. ed. 3, p. 76, n. 86. — Bril. E.rs. : 

 Leight. n. 74 : Mudd. n. (U ; 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 iu 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 gi'ows, is more or less shining, 

 especially in young plants, while the laciuise are often whitish sorediat+» 

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

 occasionally isidia are present in the costse between the faveolas. States 

 in which the isidia are numerous and crowded form the variety papiIlari.-< 

 Del. Stict. p. 144, t. 17. f. 0.3. "With us it is comparatively rare in a 

 fertile condition, though the apothecia are sometimes very numerous. 



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

 regions, rarely on mossy rocks in maritime disti-icts. — Disfi-. Gener.il 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 : Ryde 

 and .A_ppuldurcomb, Isle of "Wight : New Forest, Hants : Lydford, Tot- 

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

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

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

 Charnwood Forest. Leicestei-shire : near Ludlow, Shropshire. Cader 

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

 Dolgellv, Bettws-v-Coed, Denbighshire : Conway and Devil's Bridge, 

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

 Yorkshire ; Eglestoue and Teesdale, Durham : near Grassmere, West- 

 moreland : Cheviots, Northumberland : Patterdale and Cald- r Abbey, 

 Cumberland. Xew Galloway. Kirkcudbrightshire : near ^lotlat, Dum- 

 fi'iesshire : Pentland Hills and Turtin Hill, near Edinburgh : Inverarv, head 

 of Loch Awe, Barcaldine, and Appin. Argyleshire : The Trossach.*, Loch 

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

 Forfarshire : Dunottar Castle. Kincardineshire : Craig Cluny and Cor- 

 riemidzie, Braemar, Aberdeenshire : S. of Fort William, Inverness-shire : 

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

 Kerry ; Lough Inagh, co. Galway. 



Var. plfuroearpa Ach. Lich. Univ. p. 450 (Cromb. Exs. n. 1.37), is a 

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

 ish-black in consequence of being the host of Celicliion xtidarum, Tul. 

 In the Museum herbarium there are specimens showing this condition 

 from the following localities: — Bocconoc, Cornwall: Hafod, 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. — Thallu.s 

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

 zinae. Apothecia with the thalline margin rugoso-crenulate. — Stlcta 

 puhnonacea var. hypomela J)(A. Stict. (182-5) p. 144, t. 17. f. 64; 

 Xyl. Syn. i. p. 352. — Bril. Exs. : Cromb. n. 136. 



Approaches L. retit/era (Ach.), an exotic species, in the character of the 

 thallus beneath, which probably results from the habitat, the type it.self 

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

 fruitfd. 



