There were oaks, beeches (scarcely distinguishable from existing species), birches, planes and willows (one closely related to the living Salix candida), laurels, represented by Sassafras and Cinnamomum, magnolias and tulip trees (Liriodendron), myrtles, Liquidambar, Diospyros and ivy.
Sequoia and the tulip-tree still remain; figs are abundant; laurels are represented by Sassafras and camphor; herbaceous plants (Ranunculaceae, Cruciferae, Umbelliferae) are present, though, as might be expected, only fragmentarily preserved.
Laurel, rhododendron, and whortleberry are common shrubs in the mountain districts, and sumac, hazel, sassafras and elder are quite widely distributed elsewhere.
In the Carolinian zone the tulip tree, sycamore, sweet gum, rose magnolia, short-leaf pine and sassafras find their northernmost limit Sage brush is common to both the western arid Transstion zone and the Upper Sonoran zone, but in suitable soils of the latter several greasewoods (Artiplex confertifolia, A.
The mere enumeration of the genera will indicate how close the flowering plants are to living forms. Newberry records Juglans, Myrica (7 species), Populus, Salix (5 species), Quercus, Planera, Ficus (3 species), Persoonia and another extinct Proteaceous genus named Proteoides, Magnolia (7 species), Liriodendron (4 species), Menispermites, Laurus and allied plants, Sassafras (3 species), Cinnamomum, Prunus, Hymenaea, Dalbergia, Bauhinia, Caesalpinia, Fontainea, Colutea and other Leguminosae, Ilex, Celastrus, Celastrophyllum (Io species), Acer, Rhamnites, Paliurus, Cissites, Tiliaephyllum, Passiflora, Eucalyptus (5 species), Hedera, Aralia (8 species), Cornophyllum, Andromeda (4 species), Myrsine, Sapotacites, Diospyros, Acerates, Viburnum and various genera of uncertain affinities.