Axelrod: The Pliocene Verdi Flora of Western Nevada 131 



Qtiercus wislizenoides Axelrod 



(PI. 23, figs. 7-8) 



Quercus wislizenoides Axelrod, Carnegie Inst. Wash. Pub. 553, p. 136, pi. 29, figs. 4—9, 1944 ; 

 Axelrod, ibid., p. 162, pi. 33, figs. 2, 5, 1944; Axelrod, Carnegie lust. Wash. Pub. 590, p. 205, 

 pi. 5, fig. 5, 1950; Axelrod, Univ. Calif. Publ. Geol. Sei., vol. 33, p. 291, pi. 14, figs. 1-2; pi. 20, 

 figs. 4-5, 8; pi. 27, figs. 5-8, 1956. 



Impressions of two live oak leaves in the Verdi flora can be matched by leaves of 

 the living Quercus wislizenii DeCandolle in size and shape, and also in details of 

 venation. The leaves of Q. hannibali Dorf, which is related to Q. chrysolepis Lieb- 

 mann, also show a general relationship to the fossils. However, the wavering char- 

 acter of the secondaries in the fossils, as contrasted with the relatively straight and 

 subparallel secondaries in Q. hannibali, indicates their affinity is with the living 

 Q. wislizenii. Although the details of finer nervation are not well preserved, there 

 is no evidence of essentially subparallel relatively heavy tertiaries, a feature that 

 serves to characterize Q. hannibali; by contrast, the tertiaries of the fossils are 

 apparently irregular, like those of Q. wislizenoides. 



Occurrence. — Verdi, Nev.: U.C. Mus. Pal. (loc. P102), hypotypes nos. 2016, 

 2017. 



Family NAIADACEAE 



Potamogeton verdiana n. sp. 



(PL 17, fig. 1) 



Description. — Leaves narrow, long, and linear; total length unknown, but up to 4.0 cm. pre- 

 served; base narrowly cuneate, tip not seen; width varying from 3.0 to 4.0 mm.; midrib com- 

 paratively firm, paralleled by 2 to 3 thin secondaries; tertiaries relatively prominent, widely 

 spaced, forming crossties with the secondaries that diverge at moderate angles or nearly cross- 

 percurrent; margin entire; texture thin. 



Discussion. — Impressions of pondweed occur by the hundreds on the slabs of 

 finely laminated diatomite that occur interbedded in the sandstone-shale section 

 at the Verdi locality. These sediments apparently accumulated in small ponds on 

 the Verdi floodplain, sites that probably closely resembled modern ponds where 

 pondweed is commonly represented today. Such modern species as P. comprcssus 

 and P. latifolius show relationship to the fossil species, as do others. 



Occurrence. — Verdi, Nev.: U.C. Mus. Pal. (loc. P102), holotype no. 1980; homeo- 

 type no. 1981. 



Family NYMPHAEACEAE 



Nymphaeites nevadensis (Knowlton) Brown 

 (PI. 23, fig. 9) 



Nymphaeites nevadensis (Knowlton) Brown, Jour. Wash. Acad. Sci., vol. 27, p. 509, pi. 1, fig. 10, 

 1938 (see synonymy). 



The characteristic rootstock impressions of Nymphaea are represented in the 

 Verdi collection at the U.S. National Museum. Their occurrence in the section in- 

 dicates the presence of shallow, ponded water-bodies on the Verdi floodplain, a con- 

 clusion in harmony with the nature of the sediments. 



Occurrence. — Verdi, Nev.: U.S. National Museum. 



