This is a perennial herb growing from a caudex in the water or mud that typically reaches a height of about 0.7 meters and a spread of 0.25 meters.[9] It produces lance-shaped leaves 12 to 20 centimeters long and 4 wide on long petioles; leaves which remain submerged in water are smaller and less prominently veined. The inflorescence is mostly erect and up to half a meter tall.
It produces a wide array of small pinkish-purple three-petalled flowers that open in the morning, from June until August.[10] The fruit is a tiny achene up to 2 or 3 millimeters long clustered into an aggregate fruit of about 20 units. The seeds are reddish-brown and about 1.5 millimeters long.[4]
Cultivation
Grows best in water 15-30 centimeters deep in full sun. Suitable for USDA hardiness zones 5–8.[9]
Similar Species
The water plantain Alisma plantago-aquatica has acute leaf tips not tapering to a stalk.[11] The flowers of A. plantago-aquatica also typically open in the afternoon, and the leaves are wider.[10]
