1921. Xo. 7. STLDIES ON THE LICHEN FLORA OF NORWAY. 39 



(B. L.I, Lyngor (B. L.l, Kristianssand: Vaagsbygden (B. L. I, Sognc: Hollen 

 (SøR.I, Mandal: Skjernoen (B. L.l. — Haugastol (B. L.l. 



ÏVcsfcrii. Fitjar: Tjuaholmen (LidI, Strandebarni (Lillef.I, Fusa: Strand- 

 vik (Lillef.I, Granvin (B. L.), Sogn: Lerdal (Norm.I. 



Northern. Hadselo (Norm.I, X'ikran atypica (B. L.l. 



f. asotca AcH. is rather common, and the following few stations do not 

 give any adequate ida of its distribution. 



Soutlicni NorK'ay. Holand: SkuUerud (B. L.l, Nordmarken: Kikut I B. L.l, 

 Osterdalen: jutulhugget (B.L.I, Lille Elvedalen (B.L.I, and Tonset (B.L.I. 



Northern. Saltdalen (Somrft.I, Troms: Gibostad (B. L.l, Ramtjordcn 

 (B. L.l, and Goalsevarre (B. L.l. 



f. coniiicopioides (GravI Waln. is less common: Osterdalen: Lille Elve- 

 dalen (B. L.l, Gudbrandsdalen: Ringebu (Somrft.I. 



f. froiuü'scois (Nyl.) Wain, has only been recorded from Hardanger: 

 Tangeraas (LillefosseI. 



f. ccriiia (Nag. I Th. Fr. from Haslemo in Solor (B. L.l, Tverelvdalen 

 in Alten (Norm.I, and from Jakobselven in Varanger. 



It seems to me that the f. ccrina is only a morbid form. 



The cortex of the podetia is areolate towards the base. At the upper 

 end the areolae are discrete, either due to an intenser growth of the me- 

 dulla or to a destruction of the cortex. The areolae become more or less 

 convex or even verrucose. They are covered with a thin, sometimes quite 

 translucent cortex, which is occasional!}' quite destructed, giving rise to 

 soredia. 



If the soredia are small and scattered they may escape attention if 

 studied by the naked eye or with a lens of small power. But they are, 

 of course, quite conspicuous under the microscope (obj. 3I. — In many 

 specimens the soredia are not much developed, in others they cover the 

 whole upper part of the podetia. Such specimens have a \ery different 

 appearance from the esorediate ones. The two types have been named 

 f. stcJiiinatiiia Acii. (the corticate onesi, and f. plciirota (Flk.) Sciiafr. (the 

 sorediate ones). 



Many steimnatina plants attain full development as such, on the other 

 hand the plciirota-%\.2%t is usually formed at an early age. The two formae 

 are in my opinion only types of variation. 



If tvpical stcnmiatiiia and ph'iirnta podetia are studied under the micro- 

 scope, their external texture is seen to be essentially the same, apart of 

 the soredia. — The medulla, seen between the cortical areolae, is loosely 

 tomentose. — 



It is clear that I consider the other formae to be still less important 

 from a purely descriptive systematical point of view, but they are of great 

 interest, because they demonstrate the great variability of this ubiquitous 

 species. 



