PARMELIOPSIS.] PARMELIEI. 263 



1. P. ambigua Nyl. Not. Sallsk. pro F. et FL F. Forh. n. ser. v. 

 (1866) p. 121. Thallus stcllato-orbicular, appressed, closely aduate, 

 imbricato-laciniate, opaque, straw-coloured, sulphureo-sorediate- ; 

 beneath brownish-black ; laciniae somewhat narrow, plane, multifid 

 (K~, CaCl~). Apothecia small, plane or slightly convex, the 

 margin entire or obsoletely crenulate ; spores oblong or ovoid- 

 oblong, often somewhat curved, 0,007-11 mm. long, 0,0025-35 mm. 

 thick. Cromb. Lich. Brit. p. 37. Parmelia ambigua Borr. Eng. 

 Bot. Suppl. t. 2796 (two lower figs.); Hook. Fl. Scot. ii. p. 55 ; 

 Sm. Eng. Fl. v. p. 37 ; Leight. Lich. Fl. p. 127, ed. 3, p. 118. 

 Liclieti ambiguits Wulf. in Jacq. Coll. iv. (1790) p. 239. Parmelia 

 diffusa Mudd, Man. p. 103. Brit. Exs. : Leight. n. 373 ; Mudd, 

 n. 75 ; Cromb. n. 146. 



The thallus is not unlike that of Parmelia Mougeotii, and is more or 

 less sprinkled with soredia, which are normally convex and often con- 

 tinent. In this country the apothecia are rare. The sperruogones, which 

 are more frequent, are very minute, blackish, sparingly scattered, with 

 spermatia 0,018-25 mm. long, 0,005 mm. thick. 



Hal). About the roots of fir trees, and occasionally on old fir pales, in 

 wooded, upland, and mountainous districts. Distr. Local, though common 

 Avhere it occurs, in S., Central, W., andN. England, IS'. Wales, the Central 

 Highlands, Scotland ; not seen from Ireland. B. M. : Ighthain, Kent ; 

 Twycross and Gopsall Park, Leicestershire ; near Oswestry, Shropshire ; 

 Cwm Bychan, Merionethshire ; Ingleby Greeuhow, Yorkshire. Killin, 

 Perthshire ; Kinuordy, Forfarshire ; Mar Forest, Braemar, Aberdeen- 

 shire ; Larig Grue, Bantfshire ; Rothiemurchus, Inverness-shire. 



2. P. aleurites Nyl. Flora, 1872, p. 248. Thallus stellato-orbi- 

 cular, closely appressed and adherent, laciniato-lobed, greyish-white, 

 whitish pulverulento-sorediate ; beneath brownish-black, sparingly 

 fibrillose ; laciniae somewhat convex and rugoso-plicate in the 

 centre, plane and linear at the circumference (K_ e ow , CaCl~). 

 Apothecia small or nearly moderate, concave or somewhat plane, 

 brownish- or reddish-spadiceous, shining, the margin slightly crenu- 

 late : spores oblong or fusiformi-oblong, usually somewhat curved, 

 0,011-12 mm. long, 0,003-4 mm. thick. Cromb. Journ.Bot. 1872, 

 p. 234. Lichen aleurites Ach. Prodr. (1798) p. 117. Parmelia 

 ambir/ua Borr. Eng. Bot. Suppl. t. 2796 (two upper figs.). Par- 

 melia hyperopta Mudd, Man. p. 91 ; Leight. Lich. Fl. ed. 2, p. 478, 

 ed. 3, p. 119. 



Externally little different, except in colour, from the preceding. The 

 thallus, which is sometimes dark-greyish, is sprinkled towards the centre 

 with white, scattered, roundish soredia. In the very few British speci- 

 mens there are only one or two small apothecia with subentire margin. 

 The spermogones, also rarely present, have the spermatia 0,0023-30 mm. 

 long, 0,0005 mm. thick. 



Hnb. On the trunks of old firs near the roots and on old fir pales in 

 mountainous districts. Distr. Very local and scarce in the N. Gram- 

 pians, Scotland. B. M. : Glen Derry and Glen Dee, Braemar, Aber- 

 deenshire ; Larig Grue, Banffshire. 



