"Lastly, the Steinhauera globosa of the Altsattel Lignites in Bohemia, is likewise found in the sandstone of the vicinity of Maus; and the Platanus Hercules of Radoboj, in Croatia, has been sent to me from Armissan, near Narbonne, by M. Toumal.
“These facts would probably multiply by a more attentive study of the different localities; but as it is, they leave little doubt as to the synchronism of the greater part of these local formations.”
In the Flora of the Miocene formations, Amphigenous cryptogams occur, represented by Algæ and mushrooms; Acrogenous cryptogams, represented by mosses, ferns, and Characeæ; Monocotyledons, among which we find Naiades, Gramineæ, Liliaceæ, and Palms; of the Gymnospermous dicotyledons, Coniferæ; and Angiospermous dicotyledons, among which occur Myriceæ, Betulineæ, Cupuliferæ, Ulmaceæ, Moreæ, Plataneæ, Salicineæ, Lawrineæ, Umbelliferæ, Karolangeæ, Combretaceæ, Calycantheæ, Leguminosæ, Anacardiæ, Xanthoxyleæ, Juglandeæ, Rhamneæ, Acerineæ, Nympheaceæ, Apocyneæ, and Rubiaceæ.
"The most striking characters of this epoch consist of the mixture of exotic forms at present peculiar to regions warmer than Europe, with vegetables growing generally in temperate countries; such as the palms, a species of bamboo, Lawrineæ, Combretaceæ, Leguminosæ of warm countries, Apocyneæ, analogous, according to M. Unger, to the genera of equatorial regions, a Rubiaceæ altogether tropical, united with erables, walnuts, birches, elms, oaks, charmes, &c., genera proper to temperate or cold regions. The presence of equatorial forms, and particularly of palms, appears to distinguish this epoch essentially from the following one. Lastly, we likewise observe the very small number of vegetables with a monopetalous corolla, limited to species referred to the family of Apocyneæ by Unger, and to the genus Steinhauera, founded on a fruit which has much relation to that of Nauclea among the Rubiaceæ.
"3. Pliocene Epoch.—This epoch, embracing all the Tertiary formations superior to the fahluns of Touraine, comprehends pretty numerous localities rich in fossil vegetables, and whose position in these formations is determined as much by the ensemble of the vegetables they contain, as by their other geological characters. The Tertiary basins which, it appears to me, must serve as the basis of this Flora, both by their identity, and the numerous and carefully-studied vegetables they contain, are: 1st, That of Œningen, near Shaffouse, the species of which have been long since studied and well determined by M. Alex. Braun, whose work, though unpublished, has been communicated to many naturalists, and particularly to M. Unger.[44] 2d, That of Parschlug, in Styria, the numerous impressions of which M. Unger has collected, studied, and determined, partly published by him in his Chloris Protogæa, and presented altogether in a special enumeration of these species recently published under the title of Flora of Parschlug. In this locality alone, M. Unger has recognised and classified 140 different species; it is the most numerous local Flora with which we are acquainted, and the identity of a great number of species with those of Œningen, indicates well the synchronism of these two local formations. Such other points in Styria appear likewise to be of the same epoch, as well as many localities in Hungary so rich in silicified wood. In Bohemia, the tripoli slates of Bilin and Comothau, which contain a pretty considerable number of plants described by M. de Sternberg, are no doubt referrible to this epoch, according to the nature of these plants. Lastly, the Tertiary hills, called the sub-appennine hills of Plaisantin, of Tuscany, and a part of Piedmont, as well as the gypseous formation of Stradella, near Pavia, so rich in impressions of leaves, form part of this epoch; but, with the exception of this latter point, these formations contain, in general, few vegetables.
"In France, the Pliocene epoch probably comprehends a part of the fresh-water deposits of Auvergne and Ardêche. Thus, the slates of Menat and those of Rochesauve appear to me to furnish a Flora very similar to those of Œningen and Parschlug. With regard to the marls of Gergovia and Merdogne, near Clermont, I think they ought rather to be classed in the Miocene epoch; but this question can be settled only by a more attentive determination of the species. The Flora, which recapitulates all that has been described or named in these formations, is, however, essentially founded, as may be seen by the indication of localities, on the two basins of Parschlug and Œningen.
"The Flora of the Pliocene formations is constituted by Amphigenous cryptogams, comprehending algæ and mushrooms; by Acrogenous cryptogams, including a muscite, ferns, lycopodiaceæ, and equisitaceæ; by Monocotyledons, naiades, gramineæ, cyperaceæ, and liliaceæ; by Gymnospermous dicotyledons, coniferæ, represented by cupriessineæ, abietineæ, and taxineæ; finally, by Angiospermous dicotyledons, comprehending myriceæ, betulaceæ, cupuliferæ, ulmaceæ, balsamifluæ, salicineæ, laurineæ, thymaleæ, santalaceæ, corneæ, myrtaceæ, calycantheæ, pomaceæ, rosaceæ, amygdaleæ, leguminosæ, anacardeæ, juglandeæ, rhamneæ, celastrineæ, sapindaceæ, acerineæ, tiliaceæ, magnoliaceæ, capparideæ, sapoteæ, styraceæ, oleaceæ, ebenaceæ, ilicineæ, and ericaceæ.
"The Pliocene epoch, considered in relation to Europe, for I have intentionally excluded from the preceding list some fossils of the Antilles referred to these formations, offers as peculiar characters an extreme analogy to the existing Flora of the temperate regions of the northern hemisphere; I do not say of Europe, for this Pliocene flora comprehends many genera strangers in the present time to Europe, but proper to the vegetation of America or temperate Asia. Such are, if we admit the accuracy of the generic relations established by the botanists to whom these determinations are owing, taxodium, salisburia, comptonia, liquidambar, nyssa, robinia, gleditschia, bauhinia, cassia, acacia, rhus, juglans, ceanothus, celastrus, sapindus, liriodendron, capparis, sideroxylon, achras, and symplocos, all genera foreign to temperate Europe, but in which they have been found in a fossil state, but which, for the most part, still occur in the temperate regions of other parts of the globe.
"As to other genera still existing in Europe, but which contain only a small number of species, we find many more of them in a fossil state; such are the Erables, of which 14 species are enumerated in this Flora of the Pliocene epoch, and the Oaks, which are 13 in number. It ought to be remarked, that these species come from two or three very circumscribed localities which, in the present time, probably would not furnish, in a circuit of many leagues, more than three or four species of these genera. Lastly, another character, which I have already spoken of, and which makes this Flora to differ still further from that of our epoch, is the absence, or at least the small number and nature of the plants with Gamopetalous corollas.
"Thus, there are only twenty plants of this Flora arranged in the families of this division, and all are referrible to this group of Hypogynous gamopetales, which I have distinguished by the name of Isogynes; in the general organization of the flowers, they approach nearest to the dialypetales.