UV-reflectance in flowers of Nymphaea alba L. and Nuphar lutea (L.) Sm. (Nymphaeaceae)

Sepals, petals and stamens of Nymphaea alba and Nuphar lutea were examined with respect to their reflectance characteristics in the ultraviolet (UV) s pectral range. The measurements, done with a spectrophotometrical set-up, s upport the photographic observations of the UV-patterns of these species. I n both species floral parts contrast with a UV-reflecting circle formed by the anthers or the filaments of the stamens. In Nymphaea alba this circle i s caused by the contrast between the UV-reflecting anthers and the UV-absor bing petals and filaments, while in Nuphar lutea this contrast is accomplis hed through the highly UV-reflecting filaments around the absorbing stigmat ic disk. (C) 2000 Elsevier Science B.V. All rights reserved.