Rhamnus

Erdei, Bolgárka, Hably, Lilla, Héja, Gábor & Fodor, László, 2022, The Late Oligocene Macroflora Of Zsámbék, Central Hungary, Fossil Imprint 78 (1), pp. 298-309 : 301-302

“ Rhamnus ” warthae HEER, 1872

Pl. 3, Figs 6, 7, Pl. 4, Figs 1–4

1962 Rhamnus angustifrons ANDR. , p. 233, text-fig. 9.

1966 Styrax cf. japonica SIEB. & ZUCC. ; Andreánszky, p. 85, fig. 76.

1966 Elaeocarpus palaeolanceolatus KOLAK. ; Andreánszky, p. 94, fig 87.

1988 Symplocos sp. ; Hably, p. 44, pl. 9, fig. 6.

1989 Symplocos sp. ; Hably, p. 89, text-figs 55, 56, 58, pl. 3, fig. 1.

1993a “ Rhamnus ” warthae HEER; Hably, p. 12, pl. 2, fig. 2.

2001 “ Rhamnus ” warthae HEER; Hably, p. 6.

2015 “ Rhamnus ” warthae HEER; Hably et al., p. 296, fig. 6: 2.

M a t e r i a l. HNHM-PBO 2021.134.1.–2021.158.1., HNHM-PBO 2021.162.3., HNHM-PBO 2021.172.3., HNHM-PBO 2021.189.3., HNHM-PBO 2021.206.1.

D e s c r i p t i o n. Leaves are simple. Lamina is lanceolate in shape. Total length of lamina is up to 10 cm, width is up to 4 cm. Apex and base are acute. Margin is toothed. Teeth are very small, acute, and thin. In a coarser-grained matrix, the teeth are not even recognizable. Venation is brochidodromous. In the upper part of the lamina, secondary veins are strongly curved (see Pl. 4, Fig. 2.), and join together forming multiply loops close to the margin. Occasional intersecondary veins are observable. Intercostal tertiary venation is percurrent, dense. Course of percurrent tertiaries is sinuous, making an acute angle with the midvein. Some of the tertiaries anastomose in the lower half of the lamina.

D i s c u s s i o n. A mass occurrence of “ Rhamnus ” warthae leaves has been recorded in late Oligocene localities, in the flora of the Zsil Valley, Romania ( Staub 1887, Givulescu 1973) and in the floras of the Eger-Wind brickyard ( Hably 2001) and Csolnok ( Erdei and Wilde 2004) in Hungary. In all of these localities members of the swamp vegetation accompany the “ Rhamnus ” warthae leaves.

The palaeogeographic distribution of this species is limited to the Intra-Carpathian area of the Central Paratethyan region, e.g., Hungary and Romania ( Hably 2001) suggesting that it was an endemic species. The appearance of “ Rhamnus ” warthae HEER may be correlated with the abrupt floral change at the boundary of the early and late Oligocene ( Hably 1993b). Kvaček and Hably (1991) suggested an affinity to the genus Rubus , based on its mass occurrence in the wetland vegetation of Eger-Wind brickyard, however, the valid systematic position of “ Rhamnus ” warthae HEER has not so far been resolved.