64 BERNT LYNGE. M.-N. Kl. 



fore relatively long and stellate, central laciniae sorediate also at their ends. 

 The whole thallus covered with white prviina. Colour white or 

 in the centra! part greyish or yellowish-grey from confluent soredia of 

 that colour, lower side white at the ci re urn feren ce, dark to black 

 towards the centre, with long, much branched rhizinae of the same 

 colour. 



Our museum possesses a Finnish specimen, collected by Lang, with 

 a herbarium note (by Lang) »cum typo Acharii exacte congruens«. It 

 has narrow, elongate, very multifid, subdiscrete white laciniae, the colour 

 of the lower cortex as above described, and quite tomentose from long 

 black rhizinae. The Norwegian specimens are coarser with contiguous la- 

 ciniae, but otherwise conformable. 



Found near Kristiania: Wettre in Asker on Salix (Lynge); and near 

 Minne (Lynge). Typical states are not frequent, but it is by numerous 

 intermediate states connected with var. pityrea. The specimens from 

 Minne are quite conformable to Claud, et Harm. Lieh. Gall. No. 495 

 [Ph. piilveriilenta var. lencoleiptes Tuck. f. argyphaeoides Harm. 



var. pityrea, (Ach.) Lynge comb. nov. 



Parmelia pityrea Acharius Lieh. Univ. (1810) p. 483. — I consider 

 this variety to be the »centre«, the type of the species. The other 

 varieties are grouped around it as more or less confluent variations. 



Ex sic. Claud, et Harm. Lieh. Gall. 73, Floerke Deutsche Lieh. 

 47, Fries Lieh. Suec. 105, Havaas Lieh. Norv. 456, Hepp Flecht. Eur. 

 876, Malbr. Lieh. Norm. 70, Migula Krypt. 120, Zahlbruckner Krypt. 

 Exsic. 1980. 



var. pityrea is a coarser plant with contiguous or imbricate laciniae, 

 colour white, greyish-white or grey. Pruina white or greyish white, 

 rarely with a tinge of blue, more or less profusely distributed over the 

 whole thallus. Soredia as in f. alphiphora, their colour white or frequently 

 yellowish. Lower side occasionally entirely uncoloured, but 

 usually more or less darkened to black towards the centre. 



Found fertile in Norway (Description of the apothecia above). 



Hab. Grows on the bark of deciduous trees, but not recorded on 

 Betula. 



