Persicaria perfoliata	Fallopia baldschuanica
climber with hooks on stem and leaf nerves	climber without hooks
flowers inconspicuous, yellow-green, barely opening	flowers conspicuous, white
fruits blue to purple berries	fruits dry achenes
leaves triangular, petiole not at the margin	leaves ovate-triangular, cordate to acuminate, petiole at the margin
Photo fruits F. baldschuanica: http://www.drachtplanten.nl