Syn.: Trapa quadrispinosa Roxb., Trapa laevis J. Presl
Family: Trapaceae Dumort.
Distribution: Eurasian species – Western, Central and Southeastern Europe, Southern and Southeastern Asia, Southern Siberia, naturalized in Northern America and Australia, evidently also in Eastern Africa.
Ecology: Grows in still water of lower altitudes. Flowers from July to August.
Description: Annual herb with submerged stem, 50–200 cm long, submerged leaves pinnately divided, rosette leaves floating on water surface with rhomboid blades. Solitary flowers with 4 white petals. Very variable species.
Threat and protection: The Water Chestnut is a protected plant in some countries (e.g. Czechia, Slovakia, Poland, Hungary, Germany, Switzerland, Ukraine, Russia).
These images were taken in Czechia, Poodří, pond Bezruč (by Ladislav Kovář, September 4, 2004) and East Bohemia, pond Farář (by Naděžda Gutzerová, August 12, 2009).
