252 



C. SKOTTSBERG 



Physcia (Schreb.) Vain. (100-150). Cosmop., most numerous temp, regions. 



picta (S\v.) Xyl. Widespread trop.-subtrop. Also Hawaii. — Mt. 

 Anaptychia Koerb. (30). Widespread, mainly warmer regions. 



hypoleuca (Muhlb.) Massal. Widespread, also Hawaii. — Mt. 



pectinata (Zbr.) R. Sant. Patag. (Nahuelhuapi), Fueg.— Mt. 



Hymenolichenes. 



Cora Fr. (8). Trop.-subtrop. 



pavonia (Sw.) Fr. Mex. -Chile, south to Fueg.; St. Helena. — Mt. Mf. 



The list includes 194 species; 103 (53 %) of these are restricted to Masatierra, 

 including 3 also found on Santa Clara, 2 (i %) have only been encountered on 

 this islet, 39 (20 %) only on Masafuera; 50 (25.7 %) are listed for both islands, 

 6 of them also found on Santa Clara. The number of endemic species is 36 (18.5 %), 

 a number likely to be reduced when the lichen flora of South America becomes 

 better known; some species described by Zahlbruckner as endemic in Juan 

 Fernandez have later been found on the mainland or on Hawaii. Xew discoveries 

 will, on the other hand, be made in the islands. 



Masatierra has 153 species, of which 26 (17%) are endemic in Juan Fer- 

 nandez; the corresponding figures for Santa Clara are 11 and 3 (27.3 %) and for 

 ]\Iasafuera 89 and 15 (16.8%). Masatierra is richer in lichen species than Masa- 

 fuera; this may have something to do with the greater variety of substratum of- 

 fered by the numerous species of trees and shrubs inhabiting only Masatierra. 

 Of 100 corticolous species 62 are restricted to Masatierra, 16 to Masafuera and 

 22 occur on both islands; thus 84 species have been collected on the former and 

 only 38 on the latter. 



The greater wealth of Masatierra is also shown in the number of endemic spe- 

 cies found only on Masatierra, 21 (of 36) or 58.3%; 3 were found also on Santa 

 Clara. The figure for Masafuera is 10 = 27.7%; of these 5 belong to the highland 

 above 1000 m. Only 5 species (14%) have been found on both islands. I suppose 

 that the superiority of Masatierra depends on the greater variation of habitat. 

 Future research will, I suppose, yield numerous additional species, but I do not 

 expect that the relation between the islands will be much altered. 



It is difficult to arrive at a geographical classification of the lichens because 

 in too many cases only very general information is given: "in the tropics", "in 

 warmer regions", "in temperate regions" and so forth, and "cosmopolitan" is used 

 too generously. Statements suggesting the most surprising disjunctions are not 

 uncommon; some are probably due to wrongly named specimens. Unfortunately 

 the lichen flora of Chile is not very well known. I have tried to find out if a 

 species called cosmopolitan has been recorded for Chile. Many world-wide lichens 

 have been found in Juan Fernandez; if also found in Chile they were referred 

 to the Chilean element. 



