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--Acalypha serrulata: The Eocene genus-species of the extant Acalypha schlechtendaliana. A member of the Euphorbia family; a shrub whose modern range is Madagascar, Reunion Island, and various Islands in the Indian Ocean (excluding the Seychelles). In Madagascar, it grows from sea level to 6,500 feet.
Middle--Left to right: Persea pseudo-carolinensis and Persea praelingue (both are members of the laurel family). The former is the Eocene counterpart to the modern Persea podandenia (synonymous with Persea liebmannii), an evergreen tree now native to parts of Mexico (Chiapas, Chihuahua, Durango, Guanajuato, Guerrero, Hidalgo, Jalisco, Nuevo León, Oaxaca, Puebla, Querétaro, San Luis Potosí, Sonora, Tamaulipas, and Veracruz). Grows best in tropical deciduous and humid pine-oak forests at elevations between 1,900 and 5,900 feet. Persea praelingue is the Eocene variety of Persea lingue, now native to Argentina and Chile. In Chile, it grows best in humid areas that receive almost constant rainfall; tolerates short dry periods of no longer than a month. In interior valleys and coastal mountains it grows at elevations from 1,600 to 6,000 feet.
Bottom--Stercula ovata: The Eocene analog of the modern Sterculia lanceifolia, an evergreen small tree that presently lives in-southern China, Bangladesh, and northeast India. In China, it grows at elevations from 2,600 to 6,500 feet on forested slopes.
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 the 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.