58 BERNT LYNGE. M.-N. Kl. 



Alten (several places, M. N. BLYTT and others, Reneen (NORMAN), Vads0 

 (HAVAAS), Mortensnes (Tn. FRIES), and in the interior: Berselv (NORMAN), 

 and Skoganvarre (LYNGE). 



Physcia muscigena is a very variable plant. The variation of the 

 laciniae has been described above. The colour of the lower side is usually 

 black, but varieties with pale lower side have been described (f. lenta 

 ACH., and f. squarrosa ACH.). In our herbarium there are several speci- 

 mens in which the appressed laciniae at the circumference are black with 

 the exception of a very narrow apical zone, whereas the central erect 

 laciniae are pale, either persistently or at least for a long time. The for- 

 mation of the black colour is evidently hindered by strong insolation. 

 ACHARIUS writes apotheciis . . . margine integer* 1 . In reality the apo- 

 thecia are nearly always crenate or even appendiculate. 



Ph. muscigena is well separated from Ph. pulverulenta by the smaller, 

 narrower and more constricted spores, by the J. reaction of the hyme- 

 nium, as well as by its ascending laciniae and its peculiar habitus. Its 

 habitus is faithfully preserved even when growing on maritime rocks in 

 Southern Norway. 



Several varieties have been described, but they are connected with 

 the type by many intermediate states. I have not seen f. minuta WAIN. 

 (Thallus minor, laciniis brevioribus et angustioribus, circ. 0,75 0,33 mm. 

 latis, planis vel convexiusculis, rhizinis minus evolutis*) 2 . A specimen 

 from Dovre ( Parmelia aquila c. stippea ACH., hb. SOMRFT.) probably 

 belongs to f. minuta WAIN. 



f. lenta (Ach.). 



Parmelia pulverulenta ft lenta ACH. Lich. Univ. (1810) p. 473. 



Physcia pulverulenta var. lenta ACH. TH. FRIES Lich. Scand. I (1871) 

 p. 138. Ph. pulv. var. muscigena f. lenta ACH. HARMAND Lich. France 

 (1909) p. 636. Ph. pulv.* muscigena f. lenta ACH. WAINIO. Adjumenta I 

 (1881) p. 132. 



According to HARMAND Lich. France p. 637 SCHAERER Lich. Helv. 

 486 belongs to the f. lenta (AcH.). In our copy of the collection No. 486 



1 Lich. Univ. p. 472. 



2 Adjumenta I (1881) p. 132. 



