Revision of the early Oligocene flora of Hrazený hill (formerly Pirskenberg) in Knížecí near Šluknov, North Bohemia
Abstract
The early Oligocene flora of Hrazený hill in Knížecí village at Šluknov, the topic of Erwin Knobloch's diploma thesis, is revised and new elements not previously encountered are included, partly thanks to the use of cuticular analysis: among conifers Pinus cf. rigios (UNGER) ETTINGSHAUSEN, Taxus engelhardtii KVAČEK and Torreya bilinica SAPORTA et MARION, among angiosperms Laurophyllum medimontanum BŮŽEK et al., Platanus neptuni (ETTINGSHAUSEN) BŮŽEK et al., Engelhardia orsbergensis (WEBER) JÄHNICHEN et al., Betula alboides ENGELHARDT emend. KVAČEK et WALTHER, B. buzekii KVAČEK et WALTHER, Alnus gaudinii (HEER) KNOBLOCH et KVAČEK, Carpinus roscheri WALTHER et KVAČEK, C. mediomontana MAI, C. cordataeformis MAI, Ampelopsis hibschii BŮŽEK et al., Hydrangea microcalyx SIEBER, Oleinites hallbaueri (MAI) SACHSE and Saportaspemum cf. occidentale MAYER et MANCHESTER.
Updated taxonomy has been proposed for several other fossil species including a new combination Parvileguminophyllum haeringianum (ETTINGSHAUSEN) KVAČEK comb. n. for the small legume foliage previously called Mimosites. The plant assemblage containing 60 fossil species (1 bryophyte, 5 conifers and 54 angiosperms) has been assigned to the early Oligocene (based on age of the radiometrical dated lava flow immediately covering the fossiliferous diatomite).
The reconstructed vegetation type is interpreted as a warm-temperate mixed-mesophytic to broad-leaved deciduous forest with a high proportion of deciduous woody elements. The flora is very similar in its spectrum to adjacent sites of a similar age occurring in Seifhennersdorf in Saxony and Kundratice in the České středohoří Mountains and fits into the previously defined floral assemblage of Seifhennersdorf-Kundratice.