280 E. A. Vainio, Lecideales. 



31. Rh. hyperboreum Vain. Thallus cinereus, haud pruino- 

 sus. Epithecium aeruginosum. Perithecium KHO crystalla rubra 

 formans. 331. 



25. Rh. Inarense Vain. Thallus albidus, subpruinosus. 319. 



B. Sporae persistenter decoloratae aut diu decoloratae et 

 demum dilute obscuratae. 



O Medulla thalli jodo non reagens. 



33. Rh. Hochstetteri (Koerb.) Vain. Thallus KHO non reagens. 

 Epithecium olivaceum aut aeruginosum. 332. 



34. Rh. cinereovirens Mull. Arg. Medulla thalli KHO rube- 

 scens. 336. 



OO Medulla thalli jodo caerulescens. 



35. Rh. polycarpum (Hepp) Th. Fr. Epithecium fuligineum aut 

 rubricosum fuscescensve, KHO rubricosum. 338. 



Sect. I. Lepidoma (Link) Vain. 



Lepidoma Link Nov. PI. Gen. in Schrad. N. Journ. Bot. 3 B. 

 (1809) p. 5. Abacina b. Mykochlamys Norm. Con. Praem. Gen. Lich. 

 (1852) p. 24. Rhizocarpon a. Eurhizocarpon Stizenb. Beitr. Flechtensyst. 

 (1862) p. 160; Th. Fr. Lich. Scand. II (1874) p. 621. 



Sporae demum murali-divisae aut rarius persistenter 

 3-septatae. 



1. Rh. geographicum (L.) D.C. 



Fl. Fr. II (1805) p. 365; Koerb. Syst. Lich. Germ. (1855) p. 262; 

 Th. Fr. Lich. Arct. (1860) p. 236, Lich. Scand. II (1874) p. 622; Arn. Lich. 

 Fragm. XII (Fl. 1871) p. 150, Lich. Miinch. (1891) p. 93. Lichen geo- 

 graphicus L. Spec. Plant. II (1753) p. 1140. Lecidea geographica Ach. 

 Meth. Lich. (1803) p. 45, Lich. Univ. (1810) p. 163, Syn. Lich. (1814) p. 

 21; Nyl. Lich. Scand. (1861) p. 248; Vain. Exp. Antarct. Belg. Lich. 

 (1903) p. 31, Lich. Exp. Vegae Pitlekai (1909) p. 110. 



Exs. Fr. Lich. Suec. Exs. XIII (1827) n. 386. — Leight. Lich. 

 Brit. Exs. IV (1853) n. 128, 129. — Nyl. Lich. Mont-Dor. (1856) n. 59. 



— Fellm. Lich. Arct. (1864) n. 203. — Nyl. Lich. Pyr. Or. (1872) n. 47. 



— Norrl. et Nyl. Herb. Lich. Fenn. VII (1882) n. 347, 348. — Havaas 

 Lich. Norv. Exs. (1901) n. 47. — Malme Lich. Suec. Exs. IX (1911) 

 n. 7. 



Thallus crustaceus, uniformis, vulgo areolatus, areolis 

 planis aut convexis, vulgo laevigatis, vulgo citrinis flave- 

 scentibusve, raro p. p. cinerascentibus albidisve aut sub- 



