Abstract
The presence of Didymosphenia geminata (Lyngbye) M. Schmidt (Bacillariophyta) was revealed in the Drava river and in its affluent Rio Sesto, both flowing in the Alto Adige/Südtirol region of Italy and belonging to the Danube basin. New data are given on the distribution of the species in the Danube basin.
Acknowledgements
We wish to thank the technicians of the Environmental Agency of Bolzano/Bozen Biological Laboratory of Laives for their support during sampling, and for supplying chemical data.