Pickerel weeds are marginal aquatic plants, from across the Americas, with often lance-shaped leaves and blue flowers. We have two forms, all growing in our water garden ponds, one noticeably taller than the other. In the US Pickerel tends to refer to a couple of freshwater fish species, whilst in the UK it normally relates to a young pike. It's also used to name a few East Anglian riverside pubs!
As with all pond-margin plants, the shoots of Pontederia give three-dimensional structure to the water's edge which provides a refuge for the aquatic nymphs of dragonflies and damselflies from attentions of predatory fish, and a valuable substrate for pond-snails.The below-water sections below the water-line also provide refuge and breeding niches for newts.On the downside, they have a strong tendency to spread into dense patches by means of their rhizomes and are giving rise to concerns in natural water-bodies: all steps should be taken to avoid them escaping the confines of a garden pond.