1916. No. 8 MONOGRAPH OF THE NORWEGIAN PHYàClACEAE. 3I 



Pycnides numerous or very numerous, located in the ends of the 

 laciniae, globose or depresso-globose diam. 200 — 240//. Penfulcrium black 

 abouth the ostiohmi, otherwise uncoloured, or only locally darkened. 

 Basidia 5 — 6// long, 4—5/* thick. Pycnoconidia straight, cylindrical or 

 slightly iiicrassate at the septum, 4 — 5 (5,5).« long, i — 1,5." thick. 



React. Cortex as well as medulla distinctly yellow by KOH, 

 no colour by CaCLO-. Hymenium first blue, then black or sordid vinous 

 red by J. 



The statements of the dimensions of the spores vary : Crombie 

 16— 26X8— II, Harmand 24 — 28X10 — 13, Sandstede 16 — 24X7—10» 

 Jatta (Sylloge p. 140) 24 — 36X6//, which is certainly incorrect. 



Fhyscia aipolia is on a whole a larger plant than Ph. ^trllaris, and 

 well separated from this species by the more elongate and plane laciniae, 

 which are more closely apprcssed to the substratum, and especially by 

 the KOH-reaction of the medulla. The spores are longer, but not thicker, 

 ihan in Ph. stcllaris; large s/r//ai is-sports are so long as medium-sized 

 i:ip()/ia spores. 



Physcia concnistaits Xyl. ^ has a distinct positive KOH-reaction of the 

 medulla, and cannot, accordingly, belong to the Ph obscuro tribe. It has 

 a thick, very rugose thallus. Prof. Elkving, Helsingfors, was kind enough 

 to send me a specimen for comparison. I consider it to be merely a 

 morbid Ph. aipolia. 



The lichenologists have proposed numerous varieties of Physcia aipolia. 

 !t will be seen from the descriptions that they dift'er in characters, which 

 are very variable in the genus. It is hardly possible to attribute a great 

 systematic value to them, with the exception of the aiigitstata, which can 

 safeK' be raised to the rank of a subspecies, and perhaps to a proper 

 species (petit espèce). Acharius, the great founder of our science, arran- 

 ges the varieties into a juvenile one (f. acrita) with a pale lower side, 

 uncoloured rhizinae, and apothecia \\\\.\\ entire margin, and into two adult 

 ones: (.irradia with black rhizinae and contiguous laciniae, and f. r/z/Z/W/z/^f 

 with pale lower side and discrete laciniae. 



' Addenda nova p. 350. 



