The Flora of the Insect Limestone (latest Eocene) from the Isle of Wight, southern England

Abstract

ABSTRACTLatest Eocene fossil plant remains occur in concentrations within blue-grey micrite known as Insect Limestone near the base of the Bembridge Marls Member (Bouldnor Formation, Solent Group), Isle of Wight, southern England. Some of the previously reported taxa (collections in the Natural History Museum, London) are not preserved within the Insect Limestone. These (e.g., all Arecaceae (palms)) are excluded from the floral list. New non-destructive techniques have yielded additional taxonomic information. Leaves previously assigned to Ficus and Fagus are now incertae sedis. Wetland elements are abundant, particularly Typha, but also Acrostichum, Azolla, Potamogeton, Sparganium and others. Non-wetland elements are rare. Trees and shrubs included representatives of Betulaceae, Caprifoliaceae, Juglandaceae, Lauraceae, Rhamnaceae (the sclerophyllous Zizyphus), other flowering plants and several genera of conifers. There are rare specimens of possible herbaceous plants and propagules with plumes or awns, the latter possibly an early fossil record of Clematis. The common plant remains were probably derived from vegetation near a freshwater body, sometimes with slight brackish influence, whilst rarer elements were probably blown in from a greater distance. There is little evidence of plant–insect interaction; one leaf with small galls, a stem containing an insect larva and a possible association between stratiomyid flies and Typha.