Szekessy Vilmos (szerk.): A Magyar Természettudományi Múzeum évkönyve 54. (Budapest 1962)
Rásky, K.: Tertiary plant remains from Hungary (Upper Eocene and Middle Oligocene)
46, Fig. 8), but this fruit cannot be compared to the one found in the Upper Eocene of Óbuda. Nor could we find from the Tertiary any other fruit fragment comparable with our fossil specimen. REID & CHANDLER (1933) described some Echinocarpus seeds from the flora of the Eocene London Clay. Comparison with recent species: On the other hand, there are several recent species whose epicarpium is covered with spinelike emergencies. Such, for example, is the fruit of Bixa orellana L. On a herbarium specimen originating from Calcutta, the spines of the fruit are dense, but more shorter and less frequently spaced than on the fossil remains. Also, the fruit of Bixa orellana is much larger than the impression of the fossil one. Bixa orellana var. platicarpa WARB. (= Bixa urucurama HOFFMSG.) has smaller fruits, but their spines are also much shorter than on the fossil specimen. The fruit found in the Buda marl cannot be connected up with these recent fruits. Honckenya ficifolia W. (W T est Africa) bears a capsule covered with spines, but the fruit is doubly spinose. On the fruit of Entelea arborescens R. Bn. (New Zealand), the spines are fewer and also thicker than on the fossil find. The smaller fruit of Oncoba dentata OLIV. (Cameroun) bears comparatively longer spines, but these too are also thicker and less densely spaced than on the fossil one. So the fossil find from Óbuda cannot be identified with these fruits either. The species Hymenopyramis siamensis CRAIB. (Verbenaceae) has a capsule covered with prickly hairs, but the fruit is also larger than the fossil one. The fruit of Chaetocarpus castanocarpus (ROXB.) THWAIT (Euphorbiaceae) is also covered with spines, but it differs from the fossil impression. The most similar fruits were found in the family Elaeocarpaceae. The sphaerical fruits of Sloanea hanceana HEMSLEY are covered with dense, rigid, straight spines. However, the fruit of this recent tree growing in China is considerably larger than the Óbuda find. The fruit of Sloanea mollis GAGNEP., of Tonking, is slightly oval, its length about 1,5—2,0 cm, clothed with rigid, dense and hard spines. The fruit of this 10 m high tree comes very near to the fossil one , as regards also size. The long-spined capsule of Sloanea sigun (BL.) SCHUM. is, however, much larger. Apart from the Sloanea species from SE Asia, the fossil is well comparable also to the fruits of the Sloanea taxa in Central America. For example, the smaller fruit of Sloanea massoni Sw. (Dominica), with its size, the length and density of its spines can be favourably compared with the impression of the fossil fruit. However, the fruits of another herbarium specimen of Sloanea massoni Sw. from an island of the Caribbean are much too large to associate them with the fossil fruit. On the other hand, the fruit of Sloanea macrophylla SPRUCE (Rio Waupes) is intermediate as regards size between those of the two former species: it is also similar to the fossil one, though with stronger spines due to its greater size. Since fossil leaf remains associable with the genus Sloanea had also been found in the Upper Eocene marl, the fossil impression can, with high probability, be relegated also to the genus Sloanea. Therefore the fossil Sloaneaecarpum eocenicum can be brought into close alliance with the fruits of the recent Sloanea hanceana HEMSLEY, Sloanea mollis GAGNEP., and Sloanea sigun (RL.) SPRUCE. inSw. Asia on the one hand, and the recent Sloanea massoni Sw., and Sloanea macrophylla SPRUCE on the other.
