DERIVATION OF THE FLORA AND FAUNA 269 



serves no ])uif)ose to sa}- tliat Centaurodendron descends from some continental 

 Ceiitaurea which became arboreous under insular conditions, because the character 

 of the ray floret is entirely opposed to such a theory and Ccntaurodcndroii seems 

 to be a more ancient type than C Oitaio-ea, a relic from an ei)och {)revious to the 

 final uplift of the Andes. 



The four Cichoriaceous genera, to vvliich 7//<^?/;/;/r.'j7V7.s- of the Desventuradas 

 Is. shows some slight affinity, are even more isolated. The only other genus to 

 which they bear some resemblance is the Polynesian Fitchia, but the difi"erences 

 are too profound to allow- us to visualize an Antarctic-Pacific ancestry of the Den- 

 droseris group and it remains us to link it with the neotropical element. 



Referring to the synopsis given above the Phanerogams are rearranged in 

 the following way according to their supposed source of origin. 



I. Antarcto-tertiary element. — 62 sp. (42.2 %). 



1. Distribution pattern austral-circumpolar, bicentric or tricentric. — 33 sp. 



a. Endemic species (17): Cladium scirpoideum, Uncinia Douglasii and costata, 

 Carex berteroniana, Luzula masafuerana, Drimys confertifolia, Phrygilanthus Per- 

 teroi, Acaena masafuerana, Sophora fernandeziana and masafuerana, Gunnera pel- 

 tata, Masafuerae and bracteata, Apium fernandezianum {t), Pernettya rigida, Plan- 

 tago fernandezia, Abrotanella crassipes. 



b. Species also found on the continent (16): Danthonia coUina, Koeleria micra- 

 thera (.'), Oreobolus obtusangulus, Uncinia brevicaulis, phleoides and tenuis, Juncus 

 imbricatus, capillaceus, acutus, dombeyanus and planifolius, Libertia formosa, 

 Acaena ovalifolia, Centella triflora, Nertera granadensis, Lagenophora Harioti. 



2. Genera only found in S.America, but supposed to be of Antarctic origin. 

 The species are endemic: Escallonia Callcottiae, Margyricarpus digynus. — 2 sp. 



3. Endemic genera or species as far as known without continental American 

 affinities, either suggesting an ancient Antarcto-Pacific track east from Australasia 

 without reaching America, or having arrived along the road over the Scotia Arc 

 without leaving any traces in the present S. American flora. — 21 sp. 



a. Belonging to endemic genera (7): Robinsonia gayana, thurifera, evenia, Masa- 

 fuerae and gracilis, Symphyochaeta macrocephala, Rhetinodendron Berterii. 



b. Endemic species of genera of wider distribution (14): Peperomia berteroana, 

 margaritifera and Skottsbergii, Santalum fernandezianum, Boehmeria excelsa, Ra- 

 nunculus caprarum, Fagara mayu and externa, Halorrhagis asperrima, masatier- 

 rana and masafuerana, Euphrasia formosissima, Coprosma Hookeri and pyrifolia. 



4. Endemic species with relatives in the African sector only: Wahlenbergia 

 Larrainii, fernandeziana, Grahamae, Masafuerae and Berteroi. — 5 sp. 



5. Endemic family, possibly of old Antarctic, perhaps pre-Tertiary ancestry: 

 Lactoris fernandeziana. — i sp. 



II. Neotropical-Andean element. — 54 sp. (36.7 %). 



I. Endemic genera or species of neotropical parentage; non-endemic species 

 South American. — 31 sp. 



a. Belonging to endemic genera (4): Juania australis, Ochagavia elegans, Notho- 

 myrcia fernandeziana, Selkirkia Berteroi. 



