1. During the [Second World] War there was a population explosion of azolla [water fern] on the Avon and Kennett Canal. The locals thought it was a government plot, because the Canal went red so that the Germans would think it was a road [Watledge, Gloucestershire, November 1994].

Image: water fern (red) growing with duckweed, Lemna minor (green), Brandon Hill, Bristol; February 2015.