Is Nymphaea lotus var. thermalis a Tertiary relict in Europe?

Nymphaea lotus L. is a tropical and subtropical species of waterlilies with an African distribution. A conspicuous satellite occurrence can be found in Europe in a thermal spring in NW Romania. This population (treated as var. thermalis (DC.) Tuzson) received much attention as a potential Tertiary relict in the flora of Europe, although its relict vs. planted nature has been part of great debate among scholars during the last 200 years.