[Wikipedia] Identification Characteristics: Important identification characteristics of V. anagallis-aquatica are: flower colour (purply-blue), bracts (usually much shorter than the flower stalk, and narrow), fruit (somewhat elongated), sepals (not spreading wide open on fruiting), fruiting stalks (base not spreading at a very wide angle) and leaves (somewhat broadish, and lowest stalked).[6] Similar plants include - V. catenata flowers are white or pale pink with rosy pink veins, bracts reaching the flowers, fruits broader than long, sepals spread wide open at fruiting, fruiting stalk bases forming a large angle to the stem (c. 90 deg), leaves somewhat narrow-looking and the lowest leaves unstalked.[6] V. x lackschewitzii has almost no fruits forming, and the plant is usually noticeably large and robust with large floral spikes. (link added by Mary Ann Machi)