I9l6. No. 8. MONOGRAPH OF THE NORWEGIAN PHYSCIACEAE. 71 



(LYNGE), Land and Vang (NORMAN), Hoi (LYNGE). Evidently frequent along 

 the south and west coast and fjords: Larvik (NORMAN), Granvin and 

 Romsdalen (HAVAAS). Also at Voss (Lio) and Mjelfjell (LYNGE) in Western 

 Norway. Trondhjem: Strinden (KINDT). In Northern Norway: Saltdalen 

 (SOMMERFELT), Kautokeino (NORMAN) and Skoganvarre (LYNGE). 



f. orbicularis (HOFFM.). 



Lichen orbicularis HOFFMANN Enumeratio (1784) p. 68, tab. IX, fig. i. 



Apothecia without a corona of conspicuous rhizinae, rhizinose only on 

 the under side of the receptacle, rhizinae of the receptacle few or (very 

 rarely in Norwegian specimens) entirely wanting. 



f. ciliata, (HOFFM.). 



Lichen ciliatus HOFFMANN Enumeratio (1784) p. 68, tab. XIV, fig. i. 

 Lichen, Parmelia, Physcia ulothrix autorum. 



Apothecia with a crown of conspicuous spreading rhizinae. 



From HOFFMANN'S description it is probable that his Lichen orbicularis 

 comprises our forms as well as Physcia virella: foliolis margine verru- 

 cosis pulverulentis, . . . polline, in humido ex viridi flavescens. His 

 excellent figure is, however, entirely our f. orbicularis. 



The type of f. ciliata has apothecia with a crown of conspicuous 

 stellate, spreading rhizinae. In other apothecia the rhizinae are less nume- 

 rous, scattered under the receptacle, and for that reason only visible when 

 the lower side of a loosened apothecium is observed through the lens or 

 on a thick section. . I have examined the apothecia of more than 100 

 herbarium specimens, and innumerable plants in nature, only finding a few 

 entirely devoid of rhizinae. There is every intermediate state between 

 no rhizinae* and the typical corona. The colour varies from pale 

 ash-grey to dark greyish-brown. The variation of the colour has no 

 correlation whatever with the development of the rhizinae. 



ACHARIUS separated his Lichen ulothrix* from Lichen cycloselis* on 

 account of the rhizinose apothecia of the former species (cfr. Lich. Univ. 

 p. 482). Later authors have followed him, some of them regarding the 

 two as different species, others as two varieties. For the reasons given 

 above, I am only able to look upon them as forms of individual variation. 



