EPICUTICULAR WAX ULTRASTRUCTURE AND CLASSIFICATION OF RANUNCULIFLORAE

Epidermal surfaces of about 199 species from 66 genera of ranunculiflo rous families are examined by scanning electron microscopy. The microm orphology of their epicuticular wax crystals is presented and discusse d under taxonomic aspects. All families of the Ranunculifloraes. str. (Ranunculales, Papaverales) prove to be highly uniform: apart from a f ew exceptions they are characterized by the presence of clustered wax tubules (Berberis type), chemically dominated by the secondary alcohol nonacosan-10-ol in the species analysed. This is in marked contrast t o the Magnoliidae s. str. (Aristolochiales, Laurales s. l., Magnoliale s), which are almost uniformly defined by transversely ridged crystals of the Aristolochia type, chemically characterized by the presence of palmitone and the absence of nonacosan-10-ol. However, the Canellacea e, Nelumbonaceae, and Winteraceae produce the Berberis type tubules si milar to Ranunculiflorae. This suggests a reconsideration of the posit ion of these families and in particular for Nelumbo a close relation t o the Ranunculiflorae also based on other chemical data. Within the po lyphyletic Hamamelididae the ''lower'' families Cercidiphyllaceae, Dap hniphyllaceae, and certain genera of Hamamelidaceae are also character ized by Berberis type waxes.