Axelrod: The Pliocene Verdi Flora of Western Nevada 109 



forest lived chiefly on bordering slopes and in adjacent valleys would not preclude 

 the occurrence of a few forest trees scattered on the floodplain, in much the same 

 way that pines now straggle down the Truckee River valley to the vicinity of the 

 Verdi locality. 



As mentioned in the discussion of the geologic occurrence, thinly laminated, 

 impure diatomaceous lenses, ranging from 3 or 4 inches, up to 10 or 12 inches 



TABLE 2 

 Relationships of the Verdi Species to Living Plants 



Fossil species Similar living plants 



trees 



Abies concoloroides A. concolor (Gordon) Parry 



Pinus florissanti P. ponderosa Lawson 



Pinus prelambertiana P. lambertiana Douglas 



Pinus pretuberculata P. attenuata Lemmon 



Populus alexanderi P. trichocarpa Torrey and Gray 



Populus pliotremuloides P. tremuloides Michaux 



Populus subwashoensis P. tremula davidiana Schneider 



Quercus prelobata Q. lobata Nees 



Quercus renoana Q. engelmannii Greene 



Quercus wislizenoides Q. wislizenii DeCandolle 



SHRUBS 



Arctostaphylos verdiana A. nevadensis Gray 



Ceanothus precuneatus C. cuneatus Nuttall 



Prunus moragensis P. emarginata (Douglas) Walpers 



Ribes galeana R. roezlii Regel; other spp. 



Salix boisiensis S. scouleriana Barratt 



Salix truckeana S. gooddingii Ball 



HERBS 



Chara verdiana C. spp. 



Potamogeton verdiana P. spp. 



Nymphaeites nevadensis Nymphaea spp. 



thick, are interbedded with the sandstones and sandy shales at the Verdi locality. 

 These diatomaceous beds apparently accumulated in ponds and shallow lakes on 

 the Verdi floodplain. Many of these layers are densely matted with scores of 

 slender leaves of the pondweed, Potamogeton verdiana. They are so abundant, and 

 the plant represents such a specialized environment, that it has seemed best not to 

 include it in the leaf count (table 1) . 



All the foliar and reproductive structures comprising the Verdi record are so 

 similar to those produced by living plants there is little doubt that the fossils are 

 close relatives of modern species. The living plants that appear to be most similar 

 to the fossils are listed in table 2, in which the species are grouped according to 

 their usual growth form or habit. As judged from these data, the flora includes 10 

 trees, 6 shrubs, and 3 herbs. 



