32 BERNT LYNGE. M.-N. Kl. 



var. acrita (ACH.) WAIN. 

 Incl. var. cercidia (Acn.). 



Parmelia aipolia a acrita ACHARIUS Lich. Univ. (1810) p. 477. SOM- 



MERFELT Suppl. Fl. Lapp. (1826) p. III. 



Physcia stellaris a adpressa b. aipolia a acrita et (i cercidia TH. FRIES 

 Lich. Scand. I (1871) p. 139. Ph. stellaris var. acrita et var. cercidia 

 NYLANDER Lich. Scand. (1861) p. in. 



Physcia aipolia var. acrita (vel cercidia} WAIMO Adjumenta I (1881* 

 p. 136. CROMBIE Brit. Lich. I (1894) p. 314. HARMAND Lich. France 

 (1909) p. 619. 



This is a coarse plant of a habitus approaching to Ph. piilvemlenta 

 var. allochroa. The laciniae are contiguous, rather short and 

 broad, and usually of a slightly darker colour than var. anthelina. At the 

 circumference they are plane, in the centre with wrinkles lengthways of 

 the laciniae, more or less rugose, and furnished with many small secondary 

 laciniae. Lower side pale or dark. 



The disc of the apothecia naked or pruinose, margin entire or 

 crenate. 



I can see merely a difference of age between var. acrita and var. 

 cercidia', var. cercidia has a dark lower side and crenate apothecia. Cre- 

 nate apothecia are decidedly a mark of age, and the colour of the lower 

 side is a very variable character in the genus. 



Hab. Found on the bark of deciduous trees, especially on Populus 

 tremula. It has not yet been reported from Firjmarken, otherwise it has 

 the same distribution as var. anthelina. 



Loc. Very abundant about Kristiania and known from numerous 

 stations in Aker, Baerum, and Asker (hb. M. N. BLYTT and others). Fre- 

 quent in the southeastern lowland: Veldre (NORDHAGEN), Toten (SOMMERFELT), 

 Norderhov (NORMAN), Brandbu, Minne, and Vestfjorddalen (LYNGE). Frequent 

 in Southern, most probably also in Western Norway and in the Trond- 

 hjem district: Aas and Drebak (LYNGE), Drammen (hb. M. N. LUND), 

 Skien (HOCH), Lynger (LYNGE), Voss (LYNGE), Granvin (HAVAAS), and 

 Frosta iJemsTAD). 



Northern Norway: Salten (SOMFT.). Frequent in Tromse amt in the 

 valleys as well as along the coast on the bark of Alnus and Populus: 



