... The classical example of petal-to-stamen transition is flower of white water-lily ( Nymphaea alba s.l., Nymphaeaceae). The description in terms of classical plant morphology can not reveal all morphological variation of transitional organs. ... All the organs of the flowers were measured (2479 organs totally). ... Besides traditional petal-to-stamen transition, in Nymphaea flower we have documented intermediate organs between sepals and petals, which are close to sepals by their morphology. ...