28o C. SKOTTSBERG 



as limited by Coi'Ki.AM) 1938 (66) does not \x\q\w<\^ falklandicum [Mecodium accord- 

 ing to CcM'KLAXD p. 94), though it is closely akin to peitatiim, and H. riigosiim 

 "is to //. tuuhridi::€US€ what H . falklandiciim is to H. peltatuin' (62. 13). According 

 to CliRisr (-r^*. 146), pi'ltattou and tiinhridgense are essentially Antarctic-andine but 

 found north as far as Mexico, also reported from S. Africa and New Zealand, ex- 

 tending in insular climates to western L2urope. The conclusion would be that also 

 falkUvidicuni and rNgosiiffi should be brought to the Antarctic group. 



IlymoiopJivlluni-Mey'nigiuDi secundum, plicatiiui and tortuosum are subantarctic- 

 American in their present distribution; JMcrijigiuni is austral and extends north to 

 tropical Asia, and its origin most likely Antarctic. 



'Iliyrsoptcris. Mesozoic fossils supposed to come near this genus have been re- 

 ported from the boreal zone; besides, from the Tertiary in Chile (see below p. 399). 

 llll.l. [1J4. 1477) calls it "a remnant of a once widespread group which migrated 

 southwards, possibly in Cretaceous times, from the Northern Hemisphere". With 

 regard to its present unique station COPELANI) [6y . 175) writes: 



As juan l-'ernandez can hardly have evolved so peculiar a fern, its most reasonable 

 origin, as a juan Fernandez fern, is Antarctica, whether directly or through southern 

 Chile. Kuropean fossils have been referred to this genus, but Juan Fernandez was not 

 colonized from FAirope. 



I.op/iosor/a is exclusively neotropical at present, but if we are to believe, as 

 C<)i'i:i,AM) thinks, that the Cyatheaceae derive from Antarctica, it is unlikely that 

 Lopliosaria would be an exception. 



The Antarctic origin of Dicksonia seems very clear to judge from its actual 

 distribution pattern. To what was said above p. 222 I shall add that along the 

 track New Zealand-Australia-Xew Caledonia-Fiji (-Samoa)-Malaysia 14 species are 

 found, along the Andean path 9, and that the species of Juan F^ernandez are not 

 linked with the neotropical but with southwest Pacific species. 



'Fhc present distribution of the genus Cystopteris suggests a boreal origin. 



In its wide as well as in its more restricted sense Dryoptcris is world-wide, 

 and C()i'i;i and's remark (^7. 181) that he has little doubt that the group as a 

 whole is of southern origin (see also 6g. 122) is perhaps little more than a guess. 

 I think we can take it ior granted that hundreds of species have evolved in the 

 neotropical region, where the single Juan FY-rnandez species D. inaequalij'olia has 

 its relatives. 



rolystiiliuui . Mistern .Asia is the centre of greatest concentration ; the section 

 occurring there is, in C( )ii;i,AM)'s oj)inion, the least primitive, and we have a number 

 ot southern hi- or tricentric frjrms, among them P. vcsiiiuvi coll. The endemic P. 

 bertiricDiuui is very close to the circumj)()lar adicDitiforme. To quote CoPKLAND: "The 

 case for ;ui Antarctic origin of Polysticlnou is so clear that the evidence has long 

 been familiar even t(j those hesitant to draw the obvious conclusion" [dj. 1 81); 

 and, "Tile distribution . . . testifies clearly to its Antarctic origin" [6g. 109). 



Aythroptcris is the only fern genus found in Juan Fernandez which is absent 

 from continental America, but otherwi.se typically austral. Its Antarctic origin is 



