Pontederia cordata, common name pickerelweed (USA) or pickerel weed (UK), is a monocotyledonous aquatic plant native to the American continent. It grows in a variety of wetlands, including pond and lake margins across an extremely large range from eastern Canada south to Argentina. A few examples include northern rivers, the Everglades and Louisiana. The species grows as an emergent plant, that is, in flooded conditions, so the 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. Apart from flooding, the species is also influenced by soil fertility, tending to grow in the more fertile bays of large lakes, for example. Like many aquatic plants, it is negatively affected by salinity and grazing. It is also negatively affected by competition from other wetland plants. Like many wetland plants, it can survive unfavourable conditions as buried seeds in the soil.
The plant flowers in late summer. The purple flowers have yellow markings which may assist in attracting bees for pollination. One bee species known to pollinate the flowers is Dufourea (Halictoides) novaeangliae. 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.
This post is part of the Floral Friday Fotos meme.