I9l6. No. 8. MONOGRAPH OF THE NORWEGIAN PHYSCIACEAE. 85 



(1902) p. 165. HAVAAS Beitrage zur Kenntnis der westnorw. Flechtenflora. 

 Berg. Mus. Aarb. (1909), no. I, p. 12. OLIVIER Lichens d'Europe (1907) 

 p. 245 (169). 



Physcia lithotea f. cndococcina HARM AND Lichens de France (1909) 

 p. 648. 



I have not seen Ph. obscura f. endochrysea NYL. and var subnigricans 

 MULL., cited by HARMAND 1. c. as synonyms. 



Ex sic. ARNOLD Lich. Exsic. 533 (non vidi), and 1612 (Parmelia 

 endococcina KBR.). HARMAND Lich. Gall. rar. 102 (Ph. lithotea f. endococcina 

 HARM.). LOJKA Lich. Regn. Hung. 19. MERRILL Lich. Exsic 129 (Ph. 

 obscura var. endococcina (KBR.) TH. FR., on branches of willows, rather 

 unlike Norwegian specimens). SCHAERER Lich. Helv. 485 (Parmelia 

 obscura e eye lose Us b. saxico/a). 



Thallus growing in small, later confluent rosettes, closely appressed 

 to the substratum. Laciniae plane, distinctly stellate, pinnato-incise, and 

 very multifid, with divaricate branches, contiguous or even imbricate, 

 narrow (0,2 mm.) or broader (to 0,5 0,6 mm.), narrow laciniae eaqually 

 broad, broader widened towards their apices. Thallus esorediate, usually 

 without isidia or occasionally towards the centre with a few short, scattered 

 and slightly conspicuous isidia. The colour varies from greyish-brown to 

 almost black, when moistened almost unaltered. Lower side black. 



Thallus covered with a thin amorphous stratum. Upper cortex (20) 

 25 40 ju thick, at the exterior part greyish with indistinct hyphae, at the 

 interior part uncoloured with distinct hyphae; hyphae constrictedly sep- 

 tate. Gonidia glomerate, rarely found in the upper cortex. Medulla 

 formed of densely interlaced hyphae, at the upper part uncoloured, 

 at the lower part yellow-red (cinnabar). Lower cortex black, 

 20 25/1 thick, formed of constrictedly septate hyphae with spacious lumina. 

 Rhiziniae scattered, black, 50/4 thick. 



Almost always fertile, apothecia small, 0,5 i (1,5) mm. in diam., 

 sessile or appressed. Margin middle-thick, first entire, then crenate or 

 even shortly appendiculate. Receptacle rhizinose; cortex black at the 

 centre, uncoloured towards the margin, cortical hyphae perpendicular to 

 the surface, constrictedly septate, relatively thin-walled. Gonidia crowded 

 in the margin of the apothecia, few and scattered under the hypothecium, 

 almost absent within the black part of the cortex. Hypothecium plecten- 

 chymatous, 4050 thick. Disc plane, epruinose, pale or dark brown or 

 brownish-black. Hymenium covered with a thin uncoloured, amorphous, 



