Palynological evidence of Azolla nilotica Dec. in recent Holocene of the eastern Nile Delta and palaeoenvironment
- Cite this article as:
- Leroy, S.A.G. Veget Hist Archaebot (1992) 1: 43. doi:10.1007/BF00190700
- 88 Downloads
Megaspores, microspores and massulae of the free-floating fern, Azolla nilotica, were found in Late Holocene sediments obtained by coring in the eastern Nile Delta. Nowadays, the nearest station for this fern is southern Sudan. The determination of the species is based on spiny projections on the megaspore body and on the verrucate microspores. Palynological studies reveal that the habitat of the fern consisted of extensive papyrus marshes, now disappeared. Several causes for the disappearance of the fern from the Nile Delta are proposed amongst which the most probable is human influence which has completely modified the vegetation and the hydrology.