Sagittaria latifolia is a variably sized (2 to 20 metres (6.6 to 65.6 ft) in length) perennial growing in colonies that can cover large amounts of ground. The roots are white and thin, producing white tubers covered with a purplish skin a good distance (0.3 to 1 metre (12 to 39 in) long, 0.15 to 0.6 metres (5.9 to 23.6 in) deep) from the mother plant. It is green and white. The plant produces rosette of leaves and an inflorescence on a long rigid scape. The leaves are extremely variable, from very thin at 1 to 2 cm to wedge shaped like those of Sagittaria cuneata. Spongy and solid, the leaves have parallel venation meeting in the middle and the extremities. The inflorescence is a raceme composed of large flowers whorled by threes. Usually divided into female flowers on the lower part and male on the upper, although dioecious individuals are also found.