Aquatic Plant Encyclopedia

A Japanese native marsh plant that fans out narrow, sword-like leaves and forms colonies on rocky stream banks. Tough at the water's edge or in terrariums, but most forms decline when fully submerged; only dwarf cultivars cope under water.

A North American emergent plant (Japanese name Nagabamizuaoi) that holds glossy heart- to arrow-shaped leaves above the water and produces spikes of soft blue-violet flowers from June to October. Cold-hardy, it suits pond margins and large containers.

A South American floating plant buoyed by swollen, bladder-like petioles, bearing pale violet flowers in summer. Extremely prolific and designated a Priority Control Alien Species in Japan, so it must never escape into outdoor waters.

A South American floating-leaved plant with round leaves that produces a succession of one-day, poppy-like yellow flowers. Called mizuhinageshi in Japanese. Cold-sensitive and listed as an alien species under consideration for control, so keep it out of the wild.

A creeping marsh plant (Japanese name Uchiwazenikusa) with round, shield-shaped leaves on slender stalks. A biotope staple, but naturalised in Japan and listed as a Priority Control Alien Species. It is distinct from the Specified Invasive Hydrocotyle ranunculoides.