298 LTCHENACEI. [PHYSCIA. 



Applecross, Ross-shire. Carrigaloe, co. Cork ; Muckruss, Killarney, co. 

 Kerry. 



Form 1. virescens Nyl. Bull. Soc. Bot. t. xiii. (1866) p. 366. 

 Thallus pale-greenish. Apothecia scattered, the margin thin, entiro, 

 greenish. Form viridescens Cromb. Journ. Linn. Soc. Bot. xvii. 

 p. 572. Lichen parietinus var. 2, With. Arr. ed. 3, iv. p. 34. 



Differs from the type in the colour of the thallus, which evidently 

 results from the hahitat, since in the herbarium it again partially reverts 

 to the normal colour. The reaction with K is also less distinct or scarcely 

 any. The apothecia are few, but it is rarely seen fertile. 



Hub. On the trunks of trees in moist shady places in upland districts. 

 Distr. Among the S. and E. Grampians, Scotland ; no doubt to be de- 

 tected elsewhere. B. M. : Finlarig, Killin, Perthshire ; Drum, Aberdeen- 

 shire. 



Form 2. cinerascens Leight. Lich. Fl. ed. 3 (1879) p. 133. 

 Thallus greyish-white. Apothecia with the margin greyish, entire 

 or somewhat inflexed. Cromb. Grevillea, xv. p. 78. 



The colour of this form also depends upon the nature of the habitat. 

 It may be considered as a dealbate condition, having the reaction with K 

 fainter than in the type. It usually occurs fertile, with the apothecia 

 fairly numerous. 



Hab. On the trunks of old trees, chiefly elms, in shady places of mari- 

 time and lowland districts. Distr. Somewhat local and rare in S. and 

 Central England, in S. Scotland, and in S. Ireland. B. M. : St. Leonard's 

 Forest and near Brighton, Sussex ; Lymington, Hants ; Ilsham Valley, 

 Torquay, Devonshire ; Windsor, Berkshire ; near Cirencester, Gloucester- 

 shire ; Twycross, Leicestershire ; Malvern, Worcestershire. Cramond, 

 near Edinburgh. Carrigaloe, near Cork. 



Yar. ft. aureola Nyl. Syn. i. (1860) p. 411. Thallus orbicular, 

 plicato-rugose, vitelline or golden-yellow ; lobes concrete, dilated, 

 plicate and iuciso-crenate at the apices. Apothecia with the margin 

 at length crenulate.' Mudd, Man. p. 113 ; Leight. Lich. Fl. p. 143, 

 ed. 3, p. 132. Parmelia aureola Ach. Lich. Univ. (1810) p. 487 ; 

 Syn. p. 210. Brit. Exs. : Larb. Lich. Hb. n. 212. 



Distinguished by the plicato-rugose and more closely lobed thallus, 

 which is also occasionally somewhat granulate in the centre, and there 

 also frequently more or less zonately centrifugal. When fertile the apo- 

 thecia are numerous, the margin becoming crenate, in this respect also 

 differing from the type. 



Hab. On trunks of trees and on walls in maritime and upland districts. 

 Distr. Only here and there throughout England, in S. Wales, and in 

 E. Scotland. B. M. : near King's Lynn, Norfolk ; Withiel, Cornwall ; 

 Buxton, Derbyshire ; Twycross, Leicestershire ; Tenby, Pembrokeshire ; 

 Kendal, Westmoreland. Near Edinburgh ; Cove, Kincardineshire ; near 

 Aberdeen. 



Form congranulata Cromb. Grevillea, xv. (1887) p. 78. Thallus 



