Fast-growing, perennial fresh water plant, with a thick stem rooted in the mud, new plants form all the time where floating stolons (above-ground, modified stems) form tufted plantlets along their length. Leaves float on water surface, are dark green, flat and round; delicate flowers are bright yellow with feathery edges to the petals, they stand above the water on 20-40mm long stalks.

Altough they bear a resemblance to 'water lilies' they are not related.

After: Carl Peter Thunberg (1743-1828), Swedish botanist and physician who travelled as surgeon with ships of the Dutch East India Compnay and did extensive botanical exploration in Southern Africa and Japan. He was a student of Linnaeus.