New distribution records of Solidago ×niederederi (Asteraceae) in Austria, Italy, and Poland

The paper presents a list of 23 new records of Solidago ×niederederi, a spontaneous hybrid between the North American S. canadensis and the European S. virgaurea. The list includes 8 records from Austria, 3 records from Italy and 12 records from Poland. An increase in the number of hybrid localities over the last 10 years in Europe is pointed out and discussed.