Szekessy Vilmos (szerk.): A Magyar Természettudományi Múzeum évkönyve 57. (Budapest 1965)

Rásky, K.: A contribution to the study of Tertiary plant remains from Hungary

III. Budapest-Óbuda, Upper Eocene Maearangaephyllum palaeomonandrum n. g., n. sp. (Plate V, Figs. 15-16) Diagnosis gen. et sp. : Leaves oblong-ovate or broadly ovate. Apex acute or acuminate, base rotundate or cuneate. Margin grossly repando-dentale. Length of leaves 13—15 cm, greatest width 7—9 cm. Midrib thick, incrassate especially basad. Number of lateral veins 7—8 pairs. Laterals ascendant, emitting subsecondaries from inferior sides. Subsecondaries camptodrome or subcamptodrome. Majority of archings emitted from lower side of basal secondaries. Secondaries and subsecondaries also still prominent, and also craspedodrome on upper portion of leaf. Tertiaries — parallel and almost at right angles to secondaries — interconnecting laterals with each other and also with midrib. Texture subcoriaceous, or membranaceous. Remarks and comparison : These leaf types are best comparable to the Macarange species relegated to the family Euphorbiaceae living today in Africa. For instance, the leaf impression published on Plate V, Fig. 16, is favourably comparable to, though not wholly identical with, the leaves of the recent Macaranga zenkeri PAX. This species inhabits today the environs of Eala, Africa. On the other hand, the fossil leaf impression shown on Plate V, Fig. 15, is wellnigh identical with the leaves of Macaranga monandra MÜLL. ARG., now inhabiting the, primary forests of Bipinde, Cameroun, Africa. Of the two recent species, Macaranga zenkeri PAX is synonymous with Macaranga monandra MÜLL. ARG. The range today of the genus Macaranga includes Africa, Asia and Oceania: accordingly, the species which lived in the Praetertiary and the Tertiary had survived here in the relict floras. However, these leaves of the euphorbiaceous type had already occurred also in the Cretaceous and the Tertiary floras of Alaska and Greenland, as well as in the European Tertiary, and were now found in a richness of form in the Upper Eocene around Budapest. The picture of the fossil leaf of Maearangaephyllum palaeomonandrum, shown on Plate V, Fig. 15, evinces a definite similarity to the leaves of a young tree of the recent Actinophora fragrans WALL., that is, the again valid, Schoutenia ovata KORTH. (according to BACKERBAKHUISEN). Flower remain: Antholithus macarangaeformis n. sp. Plate I, Fig. 3. Locality: Budapest-Óbuda, Upper Eocene, marl deposit. Generotype: Plate V, Fig. 16. Coll. Nr. 62. 918. 1., and its counterpart, Coll. Nr. 62. 919. 1. Paratype: Plate V, Fig. 15, Coll. Nr. 65. 15. 1. Palaeobotanical Collection, Botanical Department of the Hungarian Natural History Museum, Budapest. Alchorncaephyllum gramhasti (RÁSKY) RÁSKY (Plate VI, Figs. 19-20) Description; Leaf, lower portion with its counterpart, excellently showing characteristical dentation of margin. Besides strong and thick midrib and secondary veins, subsecondaries also robust arching from basal secondaries. Tertiary venation comprising of a series of approximately transverse veins between midrib and secondaries. Texture coriaceous. Remarks and comparison: For a comparison with the species Alchorneaephyllum grambasti (RÁSKY) RÁSKY, we call attention to the recent Alchornea iricurana CASAR, var. genuinaPAX & HoFFM., from Brasil. The recent leaves of Alchornea iricurana CASAR are polymorphus, the juvenile, normal, and mature shapes of the leaf differing strongly between each other. These forms are all recognizable also among the fossil impressions. The remains, relegated by us formerly to the genus Sloaneaephyllum (RÁSKY, 1962), have been reallocated to the family Euphorbiaceae. There is an indubitable, great similarity in the Older Tertiary between the leaves of some genera of the families Tiliaceae, Euphorbiaceae, or Flacourtia-