Wild rice aka zizania latifolia is now thriving on the banks of the River Leie in East Flanders. The plant isn’t native to this country and poses a threat to local plants and to waterways that can get blocked. It’s unclear how the species ended up here. Indra Jacobs of the Institute for Nature and Forest Research explains that it is known as an invasive species in New Zealand, Hawaii, western Russia and eastern Europe, but that few data are available about the situation in western Europe.