1'AKMELIA.] PARMELIB1. 261 



31. P. vittata Xyl. Flora, 1875, p. 106. Thallus somewhat ex- 

 panded, lineari-laciniate, loosely adnate, smooth, greyish-glaucous ; 

 beneath naked, black ; lacinise elougate, divaricately divided, some- 

 what plane, dark-brown or blackish at the margins (K^ yeUow , CaCl~ ). 

 Apothccia pedicellate, large, badio-reddish, the margin thin, entire 

 or inflexed ; spores 0,0046 mm. long, 0,0035-45 mm. thick. Cromb. 

 Grevillea, xv. p. 76. Parmelia physodes /3. vittata Ach. Meth. 

 (1803) p. 251; Mudd, Man. p. 96 pro parte ; Cromb. Lich. Brit, 

 p. 30 pro parte ; Leight. Lich. Fl. p. 126 pro parte, ed. 3, p. 117 

 pro parte. 



Formerly regarded by authors as a variety of P. physodes, but now 

 separated by Nylander ou account of the smaller spores and shorter sper- 

 uiatia. The tballus does not apparently become sorediiferous at the 

 apices of the lacinise, and in our specimens is of a glaucous-brown colour. 

 Neither apothecia nor sperniogones occur in Britain. These latter organs 

 have the sperrnatia 0,0045 mm. long, 0,0006 mm. thick. 



Hob. On the ground in alpine places. Distr. Found only on one of 

 the higher N. Grampians, Scotland. B. M. : Cairntoul, Braemar, Aber- 

 deenshire. 



32. P. encausta Ach. ileth. (1803) p. 202. Thallus suborbicular, 

 appressed, corrugate, narrowly laciniate, unequal, greyish-white or 

 greyish-glaucous ; beneath black, naked : laciniae crowded, multifid, 

 complicate, convex or somewhat rounded, only slightly inflated at 

 the apices (K+yellow, CaCl~). Apothecia adnate, moderate or small, 

 badio-reddish, the margin crenulate or subentire ; spores 0,00710 

 mm. long, 0,005-7 mm. thick. Gray, Nat. Arr. i. p. 441 ; Hook. 

 Fl. Scot. ii. p. 54; Sm. Eng. Fl. v. p. 203; Mudd, Man. p. 97 ; 

 Cromb. Lich. Brit. p. 36. Parmelia phi/sodes var. encausta Leight. 

 Lich. Fl. p. 127, ed. 3, p. 117. Lichen encaustus Sm. Trans. 

 Linn. Soc. i. (1791) p. 83. 



Sometimes regarded as an alpine var. of P. physodes ; but in the 

 absence of any well-marked intermediate states it may be considered 

 distinct. In regions where the plant is common, the thallus varies con- 

 siderably in colour and in the character of the laciniae, but the very few 

 British specimens are sufficiently typical. The apothecia are more or less 

 scattered, at first concave, then plane, and in old plants flexuose. The 

 spermopones are frequent, minute, black, with spermatia 0,007 mm. long, 

 about 0,001 mm. thick. 



Hah. On granitic boulders in alpine places. Distr. Found on one of 

 the higher N. Grampians, Scotland. B. M. : Cairntoul, Braemar, Aber- 

 cleenshire. 



33. P. pertusa Scheer. Spic. (1840) p. 457. Thallus orbicular, 

 plano-appressed, glabrous, sinuato-laciniate, glaucous- white : be- 

 neath black, rugose, naked ; laciniae multifid, convex, minutely 

 perforate, dilated and crenato-incised at the apices (K^Tyellow, 

 CaCl~). Apothecia central, small, reddish-brown, the margin 

 entire, inflexed; spores 2-4nse, 0,0045-60 mm. long, 0,022-28 

 mm. thick. Cromb. Lich. Brit. p. 36; Leight. Lich. Fl. p. 129, 

 ed. 3, p. 120. Lichen pertuxu* Schrank, Fl. Bavar. ii. (1789) 



