Water Hyacinth (Eichhornia crassipes)

The water hyacinth (Eichhornia crassipes) is a native Brazilian aquatic pant and was introduced into Australia in the early 1900s as an aquatic ornamental  feature plant. Valued for its floral presentation, water hyacinth was released into ponds and lagoons in public parks throughout Queensland, water hyacinth has since become a major pest of creeks, rivers and dams (DAFF, 2014). Water hyacinth has thick, broad, glossy leaves that can rise up to 1m above the surface of the water. It's leaves are 10-20cm across and float on the surface of the water. It has attractive flowers (mostly pink and lavender in colour) that stick on an erect stalk, that can support a single spike of 8-15 flowers (fig.1) (Sullivan and Wood, 2012).

Figure 1: A close up picture of the water hyacinths flowers in bloom. 

Source:http://www.weeds.org.au/cgi-bin/weedident.cgi?tpl=plant.tpl&state=vic&s=&region=vm&card=W05, accessed on the 6th of May 2014.

Water hyacinths are one of the fastest growing plants, it reproduces primarily by way of runners or stolons (DAFF, 2014). Each plant can produce thousands of seeds each year, and these seeds can remain viable for more than 28 years (Sullivan and Wood, 2012). Water hyacinth has the ability to double its numbers in as little as 2 weeks (fig. 2).

Figure 2: A waterway that has been clogged with water hyacinth.

Source:http://www.coffscoastadvocate.com.au/news/plan-flush-out-killer/1367891/, accessed on the 6th of May 2014.

Water hyacinths environmental and social impacts include:

• The destruction of native wetlands and waterways, killing native flora and fauna.
• Depletion of water and loss of oxygen.
• Breeding ground for mosquitoes.
• Large infestation will clog waterways making it impossible to move aquatic vehicles through.
• Degradation of waterway quality.
• Damages infrastructure.

Ways in which this invasive weed species can be managed and controlled are:

• Removal by hand or machines such as harvesters.
• Spraying herbicides in heavily infected areas. Making to use herbicides that will not affect the water quality in the waterways affected.

Source: DAFF, 2014.

Figure 3: On the left, a woman using dried water hyacinth to make woven baskets, and on the right water hyacinth choking a waterway.

Source:http://blog.templeandwebster.com.au/kelly-upton-interior-trading-company/, accessed on the 6th of May 2014.

Water hyacinth can be used as a form of tonic for horses with skin conditions, it can also be used to make furniture (fig 3) and in some countries it is used as a cooking vegetable with the green leaves and inflorescence used (Perry, 1980).

References:

Perry, L.M. (1980) Medicinal plants of east and southeast Asia. Handbook of Energy Crops. MIT Press Cambridge.

Sullivan, P. R. and Wood, R. (2012). Water hyacinth, Eichhornia crassipes. Solms, seed longevity and the implications for management. 18th Australasian Weeds Conference. Melbourne.

Water hyacinth (Eichhornia crassipes). (2014). [ONLINE] available at: http://www.daff.qld.gov.au/plants/weeds-pest-animals-ants/weeds/a-z-listng-ofweeds/photo-guide-to-weeds/water-hyacinth. Accessed 6th of May 2014.