Exotische Salix udensis 'Sekka' kruist met inheemse wilgen in België

Non-native Salix udensis ‘Sekka’ hybridizes with indigenous willows in Belgium. Since 2013 crossings between the exotic male clone of Salix udensis Trautv. & C.A. Mey ‘Sekka’ and female S. caprea, S. cinerea, S. triandra and S. viminalis have been found at various locations in the provinces of East Flanders, West Flanders and Antwerp. Vegetative and catkin characteristics were measured. The integration status of Salix udensis ‘Sekka’, the fasciation and heterosis phenomenon, Salix udensis crossings in literature and the viability of the crossings are examined in detail.