,g(j C. SKOTTSBERG 



Chapter XI. 



The Tertiary floras of Chile and Patagonia. 



Tertiary plant fossils have been discovered in the coast region of south Chile, 

 in Patagonia along the Andes south to the Magellan Straits, and in Tierra del 

 Fuego. The richest localities are on the coast of the province of Arauco, 37°-37°30' 

 s. lat., in combination with the coal seams of Lota, Lebu etc., and east of Lake 

 Xahuelhuapi on the Argentine side. 



The Concepcion-Arauco series. — The fossil flora was examined by Eng?:i.HARDT, 

 who described more than one hundred species of angiosperms, and later by Bkrrv 

 (27). The determinations are, just as in all the other cases, based on leaf impres- 

 sions, but although Berrv found that ExGELllARirr's determinations "are usually 

 to be relied upon" (p. 75), very many of them are, as well as his own, open to 

 doubt. The species were as a rule referred to living genera, belonging to many 

 more or less important tropical-subtropical families, Annonaceae, Apocynaceae, 

 Bignoniaceae, Bombacaceae, Caesalpiniaceae, Combretaceae, Erythroxylaceae, Lau- 

 raceae, Lecythidaceae, Myrtaceae, Palmae, Sapindaceae, Styracaceae, Vochysiaceae, 

 and so forth. In general character the floraapproaches that of the Amazon basin, 

 extended, the relief of the Andes being low at that time, to the west coast of 

 the continent and reaching south at least to 40° s. lat. The flora contains "no 

 elements of the flora of Central Chile" (p. 106) — Cassia is, however, one of the 

 genera mentioned, another is Myrceitgenia, represented by several species in cen- 

 tral and south Chile (to know Myrtaceae without flower and fruit is well-nigh 

 impossible). Berrv referred the flora to the Lower Miocene, "it is surely not so 

 old as Eocene", and also younger than the Xothofagus flora in the Magellanian 

 zone (p. 115); this he considered to be of Lower Oligocene age. 



There are two gymnosperm genera in Berrv's list which seem to disturb 

 the impression of an otherwise homogeneous neotropical assemblage, Aroucaria 

 and Sequoia. The material was reexamined by Florix (pj) who showed that 

 Araucaria araucoensis Berry is a species of Podocarptis , and Sequoia chiloisis 

 Engelhardt p.p. another. These, together with a fern described by Wh\A.Y.{Lygo- 

 dium, J12) are important additions to the Arauco flora. Florix, in accordance 

 with Bruggen, refers it to the Eocene and characterizes it as follows. 



The composition of the fossil conifer vegetation, and the distributional aspects, of 

 its constituents, indicate that it derives from a warm-temperate or subtropical rain-forest, 

 more particularly a lowland podocarp-evergreen dicotylous broad-leaved tree forest, 

 growing on the coastal plain or perhaps partly on low hills not far from the coast. The 

 climate was probably characterized by great humidity and rather uniform temperature. 

 It was frostless, and warmer than the present climate of the same district (p. 26). 



The possibility that plant material from the uplands had been carried down 

 and become mixed with material from the coastal plain is contradicted by the 

 state of preservation which is the same in all cases (p. 26). 



T/ie Pichileiifii flora. — The fossiliferous beds of Rio Pichileufii are situated 

 in 41 s. lat. about 30 miles east of Lake Xahuelhuapi in a treeless steppe country. 



