Sterculia labrusca (UNGER) UNGER

Kvaček, Zlatko & Teodoridis, Vasilis, 2011, The Late Eocene Flora Of Kučlín Near Bílina In North Bohemia Revisited, Acta Musei Nationalis Pragae Series B 67 (3 - 4), pp. 83-144 : 102

Sterculia labrusca (UNGER) UNGER

Pl. 9, figs 5-6. pl. 13, figs 6-7

1850a Laurus labrusca UNGER , p. 433.

1850b Sterculia labrusca UNGER ; Unger, p. 175, pl. 49, figs 1-11.

1869 Sterculia labrusca UNGER ; Ettingshausen, p. 13, pl. 43, figs 4, 5.

1990 Sterculia labrusca UNGER ; Bůžek et al., p. 172, fig. 3.25.

Leaves simple, with thick petiole, lamina trilobate, lobes narrow and partly apically directed, partly patent, margin entire, venation tri- palmate, primaries thick, arising directly from the lamina base, secondaris veins numerous, arising perpendicularly, intersecondaries thin and parallel, venation of higher order poorly preserved.

D i s c u s s i o n: These trilobate leaves with sleder, almost parallel-sided lobes were rarely recovered at Kučlín ( Ettingshausen 1869, pl. 43, figs 4-5). This species varies in leaf size and lobes. Most of the specimens recovered in the Staré Sedlo Fm. ( Knobloch et al. 1996) are smaller, but the leaf described by Engelhardt (1876, pl. 27, fig. 17) from the Žitenice quartzite matches well that from Kučlín. The other occurrences in the European Palaeogene (e.g., Geiseltal – Rüffle et al. 1976) may differ specifically and suggest that this foliage taxon may fall into smaller morphotypes, as already recognized by Ettingshausen (1869).

The affinity of Sterculia labrusca is not fully clarified ( Knobloch et al. 1996) and the often suggested as Brachychiton ( Sterculiaceae ), is unlikely because of its modern distribution in Australia. In its epidermal anatomy the material from Geiseltal ( Rüffle et al. 1976) deviates from the standard pattern of living sterculias (lack of stellate trichomes, paracytic stomata). No other leaf anatomical data are available from other occurrences in Europe, in particular from the type locality Socka in Slovenia.

M a t e r i a l: BP 55. 2401.1, NM G 8654.