24 BERNT LYNGE. M.-N. Kl. 



The starting point for the combination Physchia stellaris (L.) Nyl. in 

 this h'mitation is Nyl. Addenda nova, — not Prodromus, — because in 

 the latter work P. stellaris comprises our stellaris, aipolia a. o. species. 



Exsicc. Arnold Lieh. Exsicc. 788 a-d., Claud, et Harm. Lieh. 

 Gall, praec. 179, Flora Exsicc. Austr. Hung. 2732 MI, Fries Lieh. Suec. 

 206 A, Hepp Flechten Eur. 878, Merrill Lieh. Exsic. 228, Migula Krypt. 

 45, RcHB. et Schub. 86, Stenh. Lieh. Suec. 73 (supr.), Tuckerman Lieh. 

 Amer. 83. Zahlbruckner Krypt. Exsicc. Vindob. 1260, 



Thallus orbicular, small or medium-sized, 2 — 4, rarely 6 — 7 cm. in 

 diam., appressed to the substratum through numerous, white or gre3'ish, 

 branched rhizinae. Laciniae at least at the circumference stel- 

 late, narrow, 0,5 — 0,7, rarely i or even 2 mm. broad, sometimes widened 

 at their apices, but quite as frequently narrowed or even pointed. They 

 are short, multifid, most frequently divaricately furcate with short interstices 

 and therefore discrete; sometimes they are pinnate and more contiguous. 

 Laciniae with crenate or crenato-incise apices, entire or slightly undulated 

 contours, and more or less unto very convex surface, smooth 

 towards the circumference, and rugose or even bullate towards the centre, 

 at least in coarse specimens. Secondary laciniae are found, but they are 

 not numerous. Laciniae epruinose or rarely slightly pruinose at their 

 apices, thallus without soredia or isidia, opaque or with a faint 

 horny splendour. Colour uniform, white or greyish white, 

 moistened unaltered or with a tinge of green. Lower side white. 



Upper cortex 20 — 40/« thick. An exterior equally thick part (18 — 25//I 

 is opaque with indistinct hyphae, an interior part of varying thickness 

 uncoloured with distinct hyphae. Cortical hyphae perpendicular to the 

 surface, sometimes almost plectenchymatous, constrictedly septate with 

 rounded articuli. Gonidia arranged in an incoherent stratum of varying 

 thickness. Its upper surface is more plane than in Ph. aipolia. Medulla 

 uncoloured with very loosely interlaced hyphae, gradually transformed in 

 the lower cortex. The hyphae of the lower cortex more closely inter- 

 laced, more thickwalled and more refractive, the majority of them more or 

 less parallel to the surface. Rhizinae 80 — 100 (i5o)/< thick. 



Apothecia numerous to very numerous, rounded or angular, due to 

 mutual pressure. Disc plane, opaque, brown or brownish black, with or 

 without pruina. Margin thick, persistent, entire or crenate, without folioli. 

 Receptacle rugose, of the same colour as the thallus or yellowish about 

 the centre. Its cortex from 80 — 140 or even 240/* thick, in the exterior 



