1 66 MERNT LYNGE. M.-N. Kl. 



to 300 m. s. m. lint tilis r((|iiir(s fiirtlui- investigation, P. sulxuirifera was 

 — as most petites espèces, utterly neglected by former investigators. 



ParmeUn subatirifrra has been confused with P. fttli^inosn var. lartr- 

 7'ireiis. The colour of the yellow soredia is not ;il\vays quite distinct. It 

 is generally stated that the whole medulla is \e-llow (Rosendahl Unter- 

 suchungen p. 432, Ckomiuk p. 252), in reality the medulla itself is white, 

 only the soredia yellow (as correctly observed by Harm and p. 55 ij. The 

 development of isidia is very variable. In some plants they at once break 

 up, forming soredia, in others the isidia are well developed. The isidia 

 of var. laetevirens are longer and narrower, occasionally branched, and very 

 fragile, the white medulla is, therefore, often seen. 



llie best distinguishing characters are: 



P. sit bail)- if era: yellow soredia, white medulla, opaque thallus, less de- 

 veloped, sorediately fatiscent isidia, 



P. fiiligiiiosn var. laetevirens: white medulla and no yellow soredia, 

 nitidous thallus, better developed, fragile isidia which are not sorediately 

 fatiscent. 



32. Parmelia subargentifera Nvl. 



Akersh. Asker: Fusdal (Lid), Leangen (B. L.), and \'ettre (B. L.). Busk. 

 Ringerike: Norderhov (B. L.), Hoi: Neraal (B. L.). 



Teleiu. Saaheim (B. L.). 



Hed. Helgøen (B. L., det. Malme). Opl. Otta saxicola (H.l, Brandbu 

 (B. L.). 



On the bark of avenue trees and on deciduous trees in open position, 

 very rarely saxicolous. 



A S. E. lowland plant, limited to the zone of the deciduous trees. 



Our specimen of Schaerer Lieh. Helv. 371: Parmelia olivaeea v.. cor- 

 ticola b. coiisparcata has neither soredia nor isidia and cannot be referred 

 to this species. According to Wain. Not. syn. lieh. (1888) p. 22 Schaer. 

 Lieh. Helv. 371 is synonymous with Parmelia subargentifera Xyl. 



The Norwegian plants agree entirely with Arnold 471b [Imbnearia 

 verruculifera Nyl.), and with Krypt. Exsicc. X'indob. 2073 {Parmelia verru- 

 culifera (Nyl.). Rosendahl (Untersuchungen p. 425 1, also cites Arnold 

 471 b, his P. verruculifera is, accordingly, also identical with ours. 



In Lieh. Beitr. Ill p. 703 Kernstock suggests the identity of P. verru- 

 culifera and P. subargentifera Nyl. Flora 1875 p. 359. Malme also is of 

 opinion that the two names are synonyma (Bruna Farm. p. 122, Lich.Exsic. 

 Suec. 404). 



I have not seen apothecia. Pycnides are rare and easily overseen, 

 owing to the dark, opaque thallus. If moistened the thallus becomes brighter 



