Variatie en hybridisatie bij enkele taxa van het genus Symphytum

Two different hybrids in the genus Symphytum were collected in the Dutch province of Limburg, the first near Terziet (2n = 36), the second in Gulpen and on the Dolsberg between Gulpen and Wijlre (2n = 44). The first mentioned plants were indistinguishable from artificial hybrids between the 2n = 40 form of S. officinale and S. asperum (2n = 32), the other hybrids were identical with the backcross of S. x uplandicum (2n = 40) with the officinale parent (2n = 48). These hybrids were compared with some other intraspecific hybrids of S. officinale and with other hybrids between S. officinale and S. asperum