Vessels in Nymphaeaceae: Nuphar, Nymphaea, and Ondinea

Roots of Nuphar, Nymphaea, and Ondinea were studied with SEM in order to determine presence of perforations in end walls of tracheary elements. Nuphar has occasional small perforations and Nymphaea has a scattering of small perforations, but no perforations were observed in Ondinea. In Nuphar and Nymphaea, metaxylem elements have helical-reticulate wall thickenings, but end walls of tracheary elements have at least some scalariform pitting; in Ondinea, end walls are identical to side walls. In all three genera, striations (thickenings) in primary walls of tracheary elements are common, as in Euryale and Victoria.