Two early Eocene vines from south-east England

Small diameter pyritized axes, commonly referred to as 'twigs', of fossil v itaceous and menispermaceous wood from the Lower Eocene, London Clay Format ion of south-east England are described here for the first time. The vitace ous twigs, which represent the earliest known occurrence of fossil Vitaceae wood, are characterized by large diameter, solitary vessels, tall wide ray s which dilate in the phloem region, scalariform intervessel pits and simpl e perforation plates. The wood anatomy supports a close relationship to the Vitaceae and in particular the genus Rhoicissus Planch. The menispermaceou s twigs are characterized by medium to moderately large vessels, simple per foration plates, alternate intervascular pitting and very broad and high ra vs. The anatomical characters support a close relationship to the Menisperm aceae and in particular the genera Tinomiscium Miers and Coscinium Colebr. However, as these fossil twigs are not exactly similar to any particular ge nus they have been placed in the organ genus, Vitaceoxylon Wheeler and LaPa sha and Menispermoxylon Vozenin-Serra, Prive-Gill & Ginsburg, with which, r espectively, they have the greatest similarity. These specimens were studie d using reflected light- and scanning electron microscopy. (C) 2000 The Lin nean Society of London.