Trapa incisa

About

Trapa incisa, the tiny water-chestnut, is a widespread species of flowering plant in the family Lythraceae. It is native to subtropical areas of northeastern India, Southeast Asia, eastern China, Korea, Japan, and the Russian Far East. A hydrosubshrub, it is typically found in freshwater ponds and swamps from sea level to 2,000 m (6,600 ft). Its chromosome number is 2n = 48, with reports of 88, 90, 92, and perhaps 96. It has been assessed as Least Concern.

Summary from Wikipedia