Pontederia cordata, is a species, belong to Pontederiaceae family and Pontederia genus. It is a monocotyledonous aquatic plant native to the American continent. Naturaly grows from eastern Canada south to Argentina. It grows in all kind of wetlands, including pond and lake margins. Pickerel weed is a perennial although, leaves and stems die in the winter, rhizomes and roots stay alive and start new growth at spring.

Pontederia cordata can grow up to 150 cm tall. The stems are smooth, emerging above the water surface and branched, each bearing a leaf and a flower spike. The leaves are shiny green, lance to heart (cordate) in shape, up to 25 cm long by 7 cm wide. Leaves appear one per stem each with a long petiole that clasps the stem. Veins of leaf blades all parallel, curved, and there is no netlike between them.

The stems of Pickerel weed keep the leaves and flowers above water. Each stem can produce a terminal flower spike 7-10 cm long. The plant starts blooming in June and continues until November. The numerous tubular flowers on the spike are violet-blue in color and have yellow markings. Each flower lasts only one day. Bees and other insects pollinate the flowers. The fruits of this plant are small and contain one seed each. Once the plant begins to produce seeds, the stem supporting the inflorescence bends to submerse the fruits and seeds. Seeds are dormant at the time of dispersal and will not germinate without stratification for 6-8 weeks.

Like many wetland and aquatic plants, Pontederia cordata can reproduce asexually by means of branching rhizomes, and hence can form large clonal stands. This plant spreads vegetatively from fragmented rhizomes. Plant reproduces from seeds and rhizomes.

Pickerel weed grows as an emergent plant, in flooded conditions. For this, plant is generally dependent upon aerenchyma in the stem to carry oxygen into the roots. Its metabolism, is, however, also tolerant of low soil oxygen. It is often found in areas where water levels fluctuate naturally, with spring flooding and later summer emergence. It is affected by salinity.

Use in landscape: Pontederia cordata and its colourful cultivars are some of the most popular and frequently used deep marginal plants.  They can be found growing happily submerged in 10 cm of shallow water or in deeper waters up to 30 cm.  This plant has an extremely important use in formal and wildlife ponds as it is favored by the emerging nymphs of Dragonflies and Damselflies who will use it as a ladder to climb up out of the water to dry out in the sun before emerging into winged adults.  It is also one of the best plants to be used in filtration beds as it is extremely greedy and will consume lots of nutrients and nitrates in the water.

There are some cultivars of Pontederia: Pontederia Alba and Pink these cultivars grow to the same size as the cordata and produce pink or white flowers. Dilatata and Lanceolata cultivars are larger growing and grow much taller (up to 150-180 cm) than the wild purple flowered Pontederia cordata species.