I9l6. No. 8. MONOGRAPH OF THE NORWEGIAN PHYSCIACEAE. 89 



Lichen pulchellus WULFEN in JAQUIN Collectanea vol. II (1788) p. 199, 

 tab. XVI, fig. 2 (miserable). 



Psora caesia HOFFMANN Plantae lichenosae (1790) p. 37, tab. VIII, fig. i. 



Parmelia caesia ACHARIUS Methodus (1803) p. 197, Lich. Univ. (1810) 

 p. 479, ACHARIUS Synopsis (1814) p. 216. Flora Danica (1849) tab. 2507, 

 fig. i (miserable). 



Physcia stellaris b. caesia. DEICHMANN BRANTH et ROSTRUP Lich. 

 Dan. (1869) p. 65. 



Physcia caesia. NYLANDER Prodromus (1857) p. 308, NYLANDER Synopsis 



(1860) p. 426, TH. FRIES Lich. Arctoi (1860) p. 64, NYLANDER Lich. Scand. 



(1861) p. 112, MULLER u. PABST: Flechten (1876) tab. V, WAIMO Adju- 

 menta (1881) p. 137, CROMBIE Brit. Lich. I (1894) p. 317, DALLA TORRE et 

 SARNTHEIM Flecht. Tirol (1902) p. 163, OLIVIER Lich. Eur. I (1907) p. 243, 

 HARMAND Lich. France (1909) p. 629, LYNGE Blad- og busklaver (1910) 

 p. 102. 



Exsic. ANZI Ital. sup. 121 (soredia not well developed), ANZI Lang. 

 312 (not like our specimens), ARNOLD Lich. Exsicc. 1449, CLAUD, et HARM. 

 Lich. Gall, praec. 74, FLOERKE Deutsche Lich. 71, FRIES Lich. Suec. 323 

 (not seen), MERRILL Lich. Exsicc. 101, MIGULA Krypt. 43, STENHAMMAR 

 Lich. Suec. 212 supr. (inf. is Ph. tenella], TUCKERMAN Lich. Amer. Sept. 86. 

 (SCHAER. Lich. Helv. 347 is not Ph. caesia}. 



Thallus middle-sized, orbicular, diam. 2 4, rarely 5 cm. Laciniae 

 closely attached to the substratum, stellate, contiguous or with imbricate 

 ends, multifid with acute angles, pinnate or furcate, equally broad (0,5 i 

 mm.) or cuneate and narrowly affixed. Small papillaceous or branched 

 secondary laciniae are frequent towards the centre. The laciniae are 

 convex, rugulose and minutely albo maculate, with a chalky 

 splendour, without isidia or pruina, but instructed with globose 

 caesious soredia, (diam. i 2 mm.), soredia more or less crowded, in 

 old thalli sometimes confluent. The soredia are found on the surface of 

 the central parts or (see var. dubia) at the end or along the margin of the 

 laciniae. Colour white or greyish-white (except the soredia), when 

 moistened the colour is almost unaltered but the white dots become more 

 conspicuous. Lower side dark with black, branched rhizinae. 



The upper cortex has an adsperse surface; at the exterior part 

 (20 25^) it is dark, grey, and impellucid, even in thin sections; otherwise 

 it is uncoloured. Cortical hyphae plectenchymatous, constrictedly 

 septate, more or less perpendicular to the surface (add KOH). The cortex 

 varies from o (soredia) to 40 70 /.i thick. Gonidia glomerate in a very irre- 



