1916. No. 8. MONOGRAPH OF THE NORWEGIAN PHYSCIACEAE. 69 



Phystia obscura et Ph. ulothrix CROMBIE Brit. Lich. I (1894) P- 3*8 

 et 319. 



Physcia orbicularis DALLA TORRE et SARNTHEIM Die Flechten von 

 Tirol (1902) p. 165. 



Physcia obscura f. chloantha et var. cycloselis et var. ulothrix HARMAND 

 Lich. France (1909) p. 643 et 646. 



Exsic. ANZI Lich. Ital. sup. 124 (Farm, obscura var. chloantha (Acn.). 

 127 (Farm, obscura f. ulothrix (Acn.)). FUNCK Crypt. Gew. 498 (Farm, 

 ulothrix ACH.)). HEPP Flecht. Eur. 596 (Lobaria obscura a doantha (Acn.)), 

 597 (L. obsc. e cycloselis a corticola}. MALME Lich. Suec. 309 (Ph. obscura 

 (EHRH.) NYL. var. ciliata (HOFFM.) WAIN.). SCHAERER Lich. Helv. 353 p. p. 

 (Parm. obscura a chloantha), 354 p. p. (Farm, obscura y orbicularis SCHAER.). 

 SOMMERFELT Plant. Crypt. Norv. 68 (Parm. cycloselis ACH.). STENHAMMAR 

 Lich. Suec. 211 (Parm. obscura FR.). TUCKERMAN Lich. Amer. Sept. 87 

 (Farm, obscura ft uiothrix FR.). ZAHLBRUCKNER Krypt. Exsic. Vindob. 577 

 (Ph. obscura var. chloantha NYL.). 



Thallus growing in small or middle-sized rosettes, diam. 4 5 cm., 

 appressed or closely appressed to the substratum. Laciniae di- 

 stinctly stellate, linear, equally broad, 0,5 i mm. broad, 4 5, 

 rarely up to 10 mm. long, truncate or rounded at the apices, repeatedly 

 usually divaricately furcate or multih'd. Laciniae discrete or occa- 

 sionally with somewhat imbricate margins, plane or slightly convex with a 

 smooth surface, without soredia or isidia, opaque, epruinose, at the 

 margin with pale stellate cilia. Colour greyish-brown or dark- 

 brown, lower side black. A cushion of long, highly interlaced, tomentose, 

 usually unbranched rhizinae is seen between the discrete laciniae. 



Thallus covered with a thin amorphous, uncoloured stratum. Upper 

 cortex 2545 (55) ," thick, at the exterior part yellowish or greyish-brown, 

 otherwise uncoloured. Hyphae regular, perpendicular to the surface, 

 constrictedly septate, almost moniliform, cell wall thin or moderately 

 incrassate. Gonidia glomerate, disposed in a somewhat incontinuous 

 stratum under the upper cortex, more rarely in the whole medulla. Me- 

 dulla white, lower cortex black, 25 40 11 thick, rhizinae ca. 40 // thick. 



Nearly always fertile; apothecia appressed, crowded, orbicular 

 with diam. 1,5 - 2,5 mm., or angular, clue to mutual pressure. Margin of 

 middle thickness, persistent, entire or crenate. Receptacle smooth or 

 rugulose, along the margin of the same colour as the thallus, otherwise black, 

 on the lower side and at the margin with black rhizinae, 



