 "Nymphaea lotus" f. "thermalis" is endemic to the thermal water of the Peţa River, Sânmartin, Bihor County, Romania.The area is protected as a nature reserve (51.0 hectares (126 acres) in size) and consists of a rivulet along with three ponds.The water has a roughly constant temperature of around 30 °C whilst the site has an average air temperature of 10–11 °C.