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

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

Remarks and comparison : The leaf remain seems to be very similar to the already described specimens from the Upper Eocene marl of Budapest-Óbuda, though it is slightly narrower. On the other hand, the margin of the Middle Oligocène leaf is considerably refolded, hence it is difficult to establish its true width. The greatest deviation is shown by the relatively denser secondary venation, a feature, however, strongly differing also on the recent Scolopia species. Some similarity is displayed in the leaf-base of the recent Baliospermum effusum PAX & HOFFMANN, but the secondaries of even these leaves are not so ascendant as on the fossil remain. The leaves of Tetrorchidium rubrivenium POEPP. & ENDL. var. fendleri MÜLL. ARG., have more elongated bases, but the tertiary venation is utterly dissimilar in arrangement, thus any comparison has to be waived. The closest resemblance to our fossil is shown by the recent Scolopia luzonensis (PRESL.) WARB. The genus Scolopia is today disjunct, inhabiting Asia, Africa, Australia, and America. In the Tertiary, it lived also in Europe. It is stil a member of certain vegetation types of relict Tertiary floras. Locality: Budapest-Óbuda, Middle Oligocène, clay deposit, Rupelian. Material: Coll. Nr. 65. 14. 1., Palaeobotanical Collection, Botanical Department of the Hungarian Natural History Museum, Budapest, Caseariaephyllum kräuseli RÁSKY (Plate IV, Fig. 10) Description; Leaf fragment oblong-ovate, length 9.0 cm, greatest width 4.5 cm. Cuneate at base, acuminate at apex. Margin of leaf densely dentate. Length of petiole-remain 3—4 mm. Midrib thick and strong, lateral veins emitted from base, ascendant, and only distal ones more arcuate. Tertiaries parallel, interconnecting horizontally midrib and secondaries. Texture coriaceous. Remarks and comparison: The Caseariaephyllum leaf of the Middle Oligocène clay deposit differs in some details from the leaf described from the Upper Eocene. Above all, the present leaf is smaller, its base elongate. In this regard, it rather resembles the leaves of some Xylosma species, but it wholly differs in the dentation and the tertiary venation. We have brought into alliance the leaf remain of also the clay deposit with the leaf of the recent Casearia fuliginosa (BLANCO) BLANCO. The genus Casearia, is pantropical, disconnected today. The occurrences in the Hungarian Middle Oligocène demonstrate that the genus had an extensive and contiguous distribution in the Tertiary, and its present occurrences are to be understood as the surviving representatives from the great flora provinces of the Early Tertiary. The species serving for comparison inhabits today the Philippines, a further corroborating evidence of the former European archipelago, closely connected partly by the recent Far East, partly by the Far West, and also by the not so distant Far South. Locality: Budapest-Óbuda, Middle Oligocène, Rupelian, clay deposit. Material: Coll. Nr. 65. 12. 1. Palaeobotanical Collection, Botanical Department of the Hungarian Natural History Museum, Budapest. Zizyphus zizyphoides (UNG.) WEYLAND (Plate III, Figs. 8-9) Description: Narrow, elongated leaves. Base usually slightly asymmetrical, apex elongately acuminate. Margins dentate, teeth generally obtuse, removed from one another. Three midribs arising from base of leaf, decurrent to apex, interconnected by secondary veins situated usually at right angles to midribs. Texture coriaceous. Remarks and comparison: The leaf remains of Zizyphus zizyphoides were found in great numbers in the Upper Eocene marl deposits of Budapest-Óbuda (RÁSKY, 1956), nor are they rare in the Middle Oligocène clay deposits. The Zizyphus leaves are frequent from the European Tertiary; their recent area is disconnected, but they might have inhabited extensive areas in the Cretaceous and Older Tertiary. Locality: Budapest-Óbuda, Middle Oligocène, clay deposit. Materials: Coll. Nrs. 65. 10. 1. - 65. 11. 1. Palaeobotanical Collection, Botanical Department of the Hungarian Natural History Museum, Budapest.