62 BERNT LYNGE. M.-N. Kl. 



rank. In my opinion it approaches Ph. muscigena more than Ph. obscura 

 - It is found on mossy ground, in the specimens associated with Ph. 

 muscigena. Intermediate states have not been observed. 



9. Physcia grisea, (LAM.) A. ZAHLBR. 



Lichen griseus LAM. Encycl. Method. Botan. vol. Ill (1789) p. 480. 



Lobaria pulveracea HOFFMANN Deutschl. Flora (1796) p. 153. 



Lichen pityreus ACHARIUS Prodromus (1798) p. 124. 



Parmelia pityrea ACHARIUS Lich. Univ. (1810) p. 483. 



Physcia puherulenta var. pityrea NYLANDER Prodromus (1856) p. 308. 

 NYLANDER Synopsis (1860) p. 420. NYLANDER Lich. Scand. (1861) p. no. 

 TH. FRIES Lich. Scand. I (1871) p. 136. LYNGE Blad- og busklaver 

 (1910) p. 104. 



Physcia pityrea (as subsp.) CROMBIE Brit. Lich. I (1894) p. 308. 



Physcia farrea f. pityrea WAINIO Adjumenta I (1881) p. 132. HAR- 

 MAND Lich. France (1909) p. 640. 



Physcia pulveracea WAINIO Lich. Sibir. merid. (1894) p. 14. 



The synonymy of this species is very intricate. According to ZAHL- 

 BRUCKNER'S Schedae ad Krypt. Exsic. No. 1980 the name of LAMARCK is 

 the valid one. 



With the exception of the var. semifarrea WAIN, the Norwegian 

 varieties of this species seem to be confluent and very difficult of limitation. 

 It is still more difficult to identify them with the numerous varieties, de- 

 scribed by other authors, when authentic specimens are not at our disposal. 



Thallus 5 9 cm. large, appressed to the substratum or with ascen- 

 ding or erect laciniae. Laciniae usually (towards the centre always) con- 

 tiguous or even imbricate, often instructed with short, narrowly affixed 

 secondary laciniae. Laciniae usually not over 5 7 mm. long, only at the 

 circumference distinctly stellate. Thallus without isidia, but sorediate along 

 the sides of the laciniae, on the central ones also at the ends. 

 On old thalli the soredia sometimes cover the whole surface. Soredia 

 white, yellowish- white or greenish. Pruina is always found on the 

 apical part of the laciniae and sometimes spreads over the whole thallus. 

 Colour white, grey, brown or cervine (often determined by the pruina), 

 moistened greenish. The colour of the lower side vary: Entirely 

 uncoloured or uncoloured at the circumference and black only in the 

 centre. 



