DERIVATION OF THE FLORA AND FAUNA 26l 



tion is a distant iMancli of an Australasian family and ranges from the uttermost 

 south alouf^ the mountains to Mexico and to Roraima in Brazil. That Antarctica 

 once played a role in the history of Driinys is proved by the Tertiary fossils 

 disco\ered in West .Antarctica. 



Lactoris is generally looked upon as a primitive member of the Ranales and 

 claimed to belong to the most primitive element in the island flora. It has no 

 relatives in America. It is no t\pical member of the Magnoliales, an Arcto-tertiary 

 order, which it needs a Croizat to derive from the Antarctic. Geographically, 

 Lactoris is a [iarallel to Dcgeneria of Fiji, but the affinities of the latter are not 

 questionable and the\- have little in common. It lies near at hand to think of the 

 small family Lardizabalaceae, endemic in Chile. 11 ITCHIN.SCJX regards Lactorida- 

 ceae as "closely related to the W'interaceae, of which it is probably a reduced 

 derivative" [14.0. II. 85) — but is the perfect trimery a result of reduction? And are not 

 the never cjuite closed carpels an indication of primitiveness? I daresay most sys- 

 tematists agree that the Polycarpicae, whether regarded as one order or split up, are 

 among the oldest living angiosperms. The distribution of W'interaceae and the 

 occurrence in the South Hemisphere of small isolated families as Degeneriaceae, 

 Lactoridaceae and Lardizabalaceae suggests that the Antarctic continent was one 

 of the centres of evolution. 



Cardai)U}i£ is a world-wide, mainly temperate and essentially boreal genus, 

 extending into the tropics and south to Fuegia and New Zealand. The 3 island 

 species, one of them endemic, were commented on above (p. 205). 



Among the numerous Chilean species of Escalloiiia, E. Callcottiae stands a 

 little apart from the rest [158); the genus is spread along the Andes and extends 

 to Brazil and Uruguay. The subfamily Escallonioideae is austral-circumpolar: Tri- 

 beles (i S. Chile-Fueg.), Valdii'ia (i S. Chile), Forgesia (i) and Berenice (i), 

 Reunion, Anopterus (2, Tasm., E. Austral), Cnttsia (i E. Kw^WdX.), Argophyllmn 

 (10 E. Austral., X. Caled.), Colmeiroa (i Lord Howe I.), Carpodetus (i N. Zeal., 

 X. Guin.), QuDitinia (15 Austral. -X. Guin.-X. Caled., Philipp.), Potiingeria (i X.E. 

 Ind.) — a distribution suggesting an Antarctic origin. 



Riibus geoides has a single near relative, R. radicals, in S. Chile. They differ 

 very much from the numerous north temperate and tropical montane species and 

 form their own section or subgenus, and their resemblance to the Tasmanian 

 R. gimnicmus Hook. Icon. Plant. Ill is no proof of affinity. They seem to represent 

 an isolated offshoot from the north which has become cut off from its source of 

 origin and found its way into the subantarctic zone. 



Acaena. Xobody if not Croizat would argue that Rosaceae are a southern 

 family, but this cannot prevent us from assuming that the Sanguisorba assemblage 

 of genera has gone through part of its evolution at least in the far south. BiTTER 

 (jj) distinguished 10 sections: I, 13 species, S. Amer.; II, i, The Cape; III, 2, 

 I S. Amer., i Hawaii; IV, i, S. Amer.; V, 8, 6 S. Amer., i J. Fern., i Tasm.; 

 VI, I, S. Amer.; VII, 28, 26 S. Amer., i Calif., i Tasm.; VIII, 64. 58 S. Amer., 

 I Tristan da C, i X. Amsterd. I., 3 X. Zeal., i X. Zeal.-Tasm.-Austral.-X. Guin.; 

 IX, I, X. Zeal.; and X, 2, X. Zeal. Two Magellanian species occur on S. Georgia 

 and I on Kerguelen. The circumpolar distribution shows no gaps. About 70% 



