COROCORO COPPER DISTRICT OF BOLIVIA 93 



Decaisne which is rather more common than the preceding 

 and recorded from Colombia to Bolivia at altitudes reach- 

 ing upward to between 11,000 and 12,000 feet. Specimens 

 of the latter were collected in the Cordillera Real east of 

 the divide east of La Paz near Unduavi at an altitude 

 of 10,725 feet, and Weberbauer records one Peruvian 

 occurrence at 12,350 feet. 



There can be no question regarding the identification of 

 this interesting fossil species and it has hence an important 

 bearing on the interpretation of the physical conditions 

 under which these late Tertiary Bolivian floras flourished. 

 The single specimen from Potosi is more elliptical in form, 

 lacking the narrowly cuneate base, there are no indications 

 of teeth and the petiole is more slender. The venation is 

 identical, however, and it may represent an individual 

 variation or possibly a second species. In view of the 

 already too finely differentiated flora recorded from these 

 localities it seems wiser to regard this single specimen as 

 simply a variant of the described species. 



The lower altitudinal limit of the genus is not known. 

 I notice records in Weberbauer's account of the Peruvian 

 flora as low as 6,500 feet, for example he records it in the 

 Urubamba valley associated with Myrteola, Escallonia, 

 Rubus, Fuchsia, Oreopanax, etc., and it is not uncommon 

 in the montana region, associated with Fuchsia, Gunnera, 

 Cinchona, Triumfetta, Weinmannia, Escallonia, Melasto- 

 matacese, etc. 



The only previously described fossil plant that at all 

 closely resembles the present species is a form from the 

 Mio-Pliocene of Central France which Marty (i) identifies 

 species of southern Asia. 



1 Marty, P., Revue General Botanique, tome 32, p. 24, pi. 12, 

 fig. 5, 1920. 



