Betula alboides ENGELHARDT

Kvaček, Zlatko, Teodoridis, Vasilis & Zajícová, Jana, 2015, Revision Of The Early Oligocene Flora Of Hrazený Hill (Formerly Pirskenberg) In Knížecí Near Šluknov, North Bohemia, Acta Musei Nationalis Pragae Series B 71 (1 - 2), pp. 55-102 : 67

Betula alboides ENGELHARDT

Pl. 15, Fig. 1–2

1870 Betula alboides ENGELHARDT , p. 16, pl. 3, fig. 22–23.

1961 Betula cf. dryadum BRONGNIART ; Knobloch, p. 266, pl. 14, fig. 3.

Leaves broadly ovate or oval, rounded at base, 26–30 mm long, 13–22 mm wide, margin simple to double dentate, midrib thin, secondary vein in 6–7 pairs, craspedodromous, at medium acute angles (47–62°).

D i s c u s s i o n. The smaller leaves of birch recovered at Knížecí and assigned by Knobloch (1961) to Betula dryadum BRONGNIART match the newly studied lectotype of B. alboides from Seifhennersdorf ( Walther and Kvaček 2007). However, we do not follow use of this fossil species also for larger forms, as suggested by Walther and Kvaček (2007), and apply a separate species B. buzekii for them, as explained below.

M a t e r i a l s t u d i e d: Leaf impressions, NM-G8588,

EK 324–327.