Coin grass, also known as mushroom grass, is a perennial emergent or wetland herb. The plant height is 5-15 cm. The stem apex is brown. The submerged leaves have long petioles, round shield-shaped, with a diameter of 2-4 cm, wavy margin, and grass green in color. The flowers are bisexual; umbellate inflorescence; small flowers are white pink. The fruit is schizocarp. The flowering period is from June to August. Its stem nodes are obvious, one by one, each node grows a leaf, which can extend continuously. Its underground creeping stem grows at an astonishing speed, spreading wherever it goes, making it one of the beautiful and easy-to-grow aquatic plants.