Eichhornia crassipes, Fam. Pontederiaceae
Free floating aquatic perennial to 65cm, trailing fibrous feathery black to purple root system to 1m long.
Restricted invasive plants Category 3
Plants declared invasive under the Biosecurity Act 2014, that are present in QLD. Not to be distributed or disposed of.
|Form or habit:
Simple, basal, clustered dark green stiffly erect with rounded blades, 20-120 x 30-100mm, and swollen spongy bulbous stalks that provide buoyancy.
Blue, Yellow, Lilac
|Showy 6-petalled about 40mm long, 5 lilac coloured, 1 much larger with darker blue/purple and yellow centre; borne in dense erect spikes projecting above the foliage.
|Brown capsules, about 15mm long, form on a recurved stem that becomes submerged before releasing the many egg-shaped ribbed seeds, 1mm long.
|Food source for:
|No toxicity known
|Spread by: floods waters and wind spreading vegetative fragments, daughter plants remain attached until broken off by wind or physical damage. Seeds and plants washed out of/or discarded from ornamental ponds. Invades/threats: forms dense mats, eventually choking the entire surface of stagnant or slow-moving water bodies. Destroys native habitat, depletes water of oxygen and increases water loss through evaporation. Notes: introduced to Brisbane in the early 1900’s as an ornamental pond plant and released into ponds and lagoon in public parks throughout Queensland. An infestation can double in size every week. Seeds viable for up to 15 years. Provides breeding ground for mosquitoes, can entangle swimmers and stock, impedes water traffic, blocks irrigation equipment. Category 3 restricted invasive plant under the Biosecurity Act 2014, it must not be given away, sold, or released into the environment without a permit. The Act requires everyone to take all reasonable and practical steps to minimise the risks associated with invasive plants and animals under their control. This is called a general biosecurity obligation (GBO).
|Mackay Regional Pest Management Group (2018) Weeds of the Mackay Whitsunday Region Second Edition.