Eichhornia azurea is a perennial aquatic plant with submersed and emersed leaves, up to 100 cm tall. In the neotropics, with other aquatic plants, it forms floating masses that obstruct navigation. Propagation is by whole plants, stem fragments, fruits, and seeds. E. azurea was introduced into the U.S. as an aquatic ornamental but has not become established as a weed here. Anchored water hyacinth smothers the surface of creeks, lakes and other water bodies. It has not yet been found in Australia.
Anchored water hyacinth is a prohibited invasive plant under the Biosecurity Act 2014.
Native to Mexico, Central America and South America, also Jamaica. Introduced to India, Iran, and the United States. Currently not known to exist in Queensland.
E. azurea is a large, long-lived, mat-forming perennial which most commonly occurs in permanent water bodies. Predominant in mud along rivers, lakes, marshes, canals, the channel between rivers and lakes and in the littoral zone of lakes (Barrett, 1988). It prefers open and slow-moving water environments.
Eichhornia azurea grows rapidly and can very quickly form expansive mats of floating plants, completely covering even large lakes. This complete coverage of the surface of the water blocks sunlight and depletes the oxygen available to the rest of the aquatic community. It can make the body of water uninhabitable by other aquatic organisms. Can aso impact upon infrastructure such as irrigation pumps, pontoons and bridges.
Leaves are glossy, round, generally broad-ovate, 5–16cm long, 2–16cm wide. Stems are smooth and branched.
Flowers are held on erect stems 8–12cm above the surface of the water. There can be from 7 to as many as 50 flowers per stem. Each flower blooms for only a day. Flowers are attractive, funnel-shaped, purple, with 6 toothed petals 1–3cm long. Seeds are 1–2mm long. Flowering can occur from summer through Autumn.
Reproduction is both by seed and vegetative propagation, and the propagules can be carried out by the drift from the upper stream to downstream Vegetative reproduction is not as extensive as in water hyacinth (E. crassipes). The seeds may be carried by birds.