Due to its popularity as a pond plant, and subsequent escape into rivers, it has established as an invasive alien species in parts of Europe, Australia, Africa and Japan.

[1][2][3] It was one of five aquatic plants which were banned from sale in the UK from April 2014, and was the first prohibition of its kind there.

[6] This implies that this species cannot be imported, cultivated, transported, commercialized, planted, or intentionally released into the environment in the whole of the European Union.

[8] Leaves grow on petioles up to 35 cm long, and are round to kidney-shaped, with 3–7 lobes and crenate to entire margins.

[8] The South American weevil Listronotus elongatus lays eggs on and eats the floating pennywort, and larvae also eat into the stems, reducing the pennywort's ability to grow.