AzollaSpecies from the Pleistocene of the Central North Sea Area

Abstract

Reproductive organs of Azolla species (Salviniaceae) from the Lower and Middle Pleistocene of the Dansk Nordsø A-1 and A-2 boreholes, central North Sea area, were studied by means of scanning electron microscopy. A new species, Azolla danica, based on massulae is proposed. The megaspore apparatuses of Azolla filiculoides Lam. and Azolla tegeliensis Florschütz are described and the possible affinity of A. danica to A. tegeliensis is discussed. It is concluded, that the A. danica massulae can be regarded as the previously unknown massulae of A. tegeliensis. A tentative, chronostratigraphical subdivision of the Quaternary section is given. The record of A. tegeliensis is the first proof of the presence of limnic deposits of the Tiglian interglacial within Danish territory.