Top to bottom--Fossil leaves from the upper Eocene La Porte Tuff, secured from an abandoned hydraulic gold mine in the vicinity of La Porte, Sierra Nevada, California. Top and middle--Quercus nevadensis: The Eocene equivalent of the extant Lithocarpus corneus var. hainanensis, native to China (southern Fujian, Guangdong, Guangxi, southern Guizhou, Hainan, southern Hunan and eastern Yunnan), Vietnam (northeast), and Taiwan; prefers elevations below 3.200 feet along sunny mountain slopes and drier areas in evergreen forests.
Bottom--Petrea rotunda: The Eocene variety of Petrea volubilis, a vine in the Verbenaceae family; common names include purple wreath, queen's wreath, sandpaper vine, and nilmani. Native to Belize, Bolivia, Brazil (North, Northeast, South, Southeast, and West-Central), Cayman Is., Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, Florida, French Guiana, Guatemala, Guyana, Haiti, Honduras, Jamaica, Leeward Is., Mexico (Central, Gulf, Northeast, Southeast, and Southwest), Nicaragua, Panamá, Paraguay, Peru, Puerto Rico, Suriname, Trinidad-Tobago, Venezuela, Windward Is.
Photographs courtesy Susan S. Potbury, from her publication The La Porte Flora Of Plumas County, California, originally issued November 25, 1935; contained in Carnegie Institute of Washington Publication 465, 1937, Eocene Flora Of Western America. I edited and processed the images through photoshop; adding thr green border, for one.
Note--Always check with the US Forest Service to determine if unauthorized fossil collecting is allowed at the La Porte locality.