Cretaceous and Tertiary Plants of Europe

Miocene.

One of the earliest described and most famous of Tertiary floras was obtained from the silted up lake of Oeningen in Switzerland. From this Oswald Heer recorded hundreds of species. As his work needs revision, it will be better to take as a type of a Miocene flora the almost equally famous brown-coal of central Europe. Much recent work has been done on brown-coal material derived from various localities by the late Dr. V. Menzel and Dr. R. Krausel. Numerous conifers are found—Sequoia, Taxodium, and Glyptostrobus. The walnut family is strongly represented by American and Asiatic forms. Catkin-bearing trees are abundant. Among exotic genera are Ampelopsis, Acantho panax, Aralia, Cinnamomum, Elaeodendron, Lindera, Liquidam bar, Magnolia, Persea, Symplocos. Among European genera are Cotoneaster, Paliurus, Sorbus, Spiraea, Trapa, Zizyphus, plane, plum, hawthorn, blackberry, maple, Euonymus, holly buckthorn, lime and ash. In this flora are found forms so near the living as to be named as mere varieties. It must be remarked, however, that genera found in Europe are still often represented by species of exotic relationship.

The transition from Miocene to Pliocene is well represented in the old volcanic region of central France. E. M. Reid has de scribed from fruits and seeds a late Miocene (or Mio-Pliocene) flora from Pont-de-Gail. Among alien genera are Actinidia, Ame thystia, Cleomella, Clerodendron, Ehretia, Epipremnum, Mag nolia, Meliosma, Menispermum, Phellodendron, Polanisia, Sym plocos, Trichosanthes. All are of east Asian or American affinity. There are besides numbers of European genera which cannot here be named.

Pliocene.

The Lower Pliocene flora of Mougoudo (Cantal) is a little newer. It was examined by Prof. L. Laurent who recorded exotic Lauraceae, Rhamnaceae and Malvaceae, also Zel kova, Abronia, Cissus, Grewia, Sterculia and Paulownia.

The largest known Lower Pliocene flora is the Reuverian from the Dutch-Prussian border. It was studied by Prof. Laurent and by C. and E. M. Reid. Among exotics are Actinidia, Araucaria, Aralia, Brasenia, Carya, Epipremnum, Euryale, Glyptostrobus, Karwinskia, Magnolia, Meliosma, Menispermum, Myrsine, Nel umbium, Nyssa, Phellodendron, Proserpinaca, Pseudolarix, Ptero carya, Sequoia and Zelkova, besides many others. European gen era are now numerous. Many living species occur, some of them European.

Similar evidence comes from the Rhone valley where M. l'abbe Georges Depape has recorded Buettneria, Carya, Cinnamomum, Diospyros, Ginkgo, Glyptostrobus, Laurus, Liquidambar, Lirio dendron, Oreodaphne, Persea, Pterocarya, Sapindus, Sassafras, Torreya, Zanthoxylon and Zelkova, amongst exotic genera.

In the Middle Pliocene a great change occurred in the European flora. Very rapidly the old exotic plants disappeared and European plants took their places, almost with a rush. In the flora of Tegelen (Holland) but a few stragglers of the exotic genera re main : Actinidia, Dulichium, Euryale, Magnolia, Phellodendron, Pilea and Pterocarya. 84% of genera were European and 82% were represented by allies of European species. By the close of the Pliocene, i.e., the end of the Tertiary period, the Cromer forest bed flora shows an almost exclusive European alliance. The old flora had gone.