Perennial aquatic plant with two types of branches: long branches creep along the bottom of the water, resembling horizontal stems; short branches grow from the joints of the long branches.

The petiole length varies greatly, the leaves are ovate, measuring 3 to 5 cm in length and 3 to 5 cm in width. The upper surface is green with purple-black spots along the edge, while the lower surface is purple, with the base deeply cleft into a heart shape. The flowers are large and prominent, being the largest in the genus with a diameter of about 2.5 cm. The corolla is yellow, five-lobed, with the lobes having bristle-like edges. The center of the corolla lobes features a distinct wrinkle, and the lobes have hairs on the sides of the mouth, with a tuft of hair at the base of each lobe, and five glands present. There are five stamens inserted between the lobes, and the pistil has a two-lobed stigma. The fruit and seeds are also particularly unique in the genus, with the ovary base having 5 nectar glands, a two-lobed stigma. The capsule is ellipsoid and does not split open. The seeds are numerous, round, and flat. The fruit is flat, and the seeds are also flat with bristles along the edge; whereas, other species in the genus have ellipsoid fruits and lens-shaped seeds.

Water Lettuce is a shallow-water plant of the Pontederia genus. The stems are slender, soft, and highly branched, creeping and rooting at the nodes, floating on the water surface or growing in the soil. The plant varies greatly in height, with ovate leaves measuring 3 to 5 cm in length and width, a green upper surface with purple-black blotches at the edges, and a purple underside with deeply heart-shaped bases. The flowers are large and prominent, the largest in the Pontederia genus, with a diameter of about 2.5 cm, five-lobed, with the lobes ending in whiskers. The corolla lobes have a distinct wrinkle in the middle, and the margins have hairs, with tufts of hair at the base of each lobe, and five glands. There are five stamens inserted between the lobes, and the pistil has a two-lobed stigma. This species is particularly distinct with five nectar glands at the base, a two-lobed stigma, and non-lobed, round bracts. The seedlings have robust cotyledonary axes. The cotyledons are elongated with pointed tips and stems. The first leaves are heart-shaped with rounded tips and a heart-shaped base, lacking distinct veins, and with long stems. Water Lettuce typically renews from dryness in March to May, flowers and fruits from May to October, and the fruits mature in September to October. The plant flowers and fruits simultaneously, and upon the first frost, the above-water parts die. In warm regions, the green grass period lasts about 240 days, and the flowering and fruiting period extends to about 150 days. Water Lettuce has a strong regenerative capacity.