Weed of the Week - Amaranthus viridis (Green Amaranth)

Weed of the Week - Green Amaranth

A. viridis leaves and seed spikes
Photo: Luke Bull 2016

Binomial: Amaranthus viridis

Common: Green Amaranth, Slender Amaranth

Habitat: Suburban & Disturbed areas, 

Appearance

Typically growing 50cm, but often upto 1m, in height. Green Amaranth leaves are alternately aligned and flowers form in long clusters from the axils. Branches are often striped with purple and/or featuring a slightly red tinge.  Flowers are usually red in color, but may also appear green, male and female flowers are distinctly different and often seen simultaneous on the same plant. Amaranth is very easy to identify and once you have seen one you will find them everywhere.

Source: AVH 2016

Invasive Species Declarations / Distribution

In most Australian states A. viridis is not a declared species it is marked for control and investigation by many Local Governments.

The prolific nature of this plant in built up areas should give a clear indicator as to its invasive potential. As can be seen by the distribution map provided by the Australian Virtual Herbarium ( AVH 2016) amaranth are traditionally found in heavily populated areas thriving on disturbed surfaces. Care should be taken and harvest of plants prior to seed maturing is advisable for any exotic species you have in your gardens.

Culinary Uses

 Amaranth contains a broad array of essential nutrients and is particularly noted for high content of :- calcium, iron, phosphorous and carotenoids within both the seed and leaves. The grain of green amaranth is able to be processed in similar fashion to all other small grains including :- popped, flaked, extruded and ground flour. Amaranth Spp. are suspected of having high nitrate content making them not ideal for stock grazing.

Both the leaves and seeds are usable in a culinary context. Leaves can be cooked or used as salad much like spinach. The fresh leaves and stems are preferred for consumption and plants grown in a well  maintained spot such as a veggie garden will produce the tastiest shoots, Most commonly used in stews and other wet dishes amaranth is also eaten raw or boiled on its own and served as a healthy addition to any meal.

Source: (Alegbejo 2013)

In mexico the popped seeds of green amaranth are prepared with sugar into a sweet treat called "Allegría" which is very popular in many areas of the country.

Medicinal Uses

Commonly used in areas of India as an anti-bacterial (anti-microbial) several studies have been conducted to confirm the efficacy as a sole treatment as well as in conjunction with other medicines (Sowjanya 2014). Other traditional uses include Studies have also shown that the consumption of the seeds or oil is beneficial in reducing blood pressure and cholesterol levels.

Other Uses

Other potential uses include creation of non toxic red pigments (anthocyanin). Also used to produce aquallene an oil used in an array of industries including cosmetics, computer and phamaceutical.

Images

A. viridis leaves and seed spikes
Photo: Luke Bull 2016

A. viridis plant, growing in grass
clippings on top of a rock surface.
Photo: Luke Bull 2016

References

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia

Australian Virtual Herbarium 2016. "Occurence Record Distribution Mapping".  http://avh.ala.org.au/occurrences/search?taxa=Amaranthus+viridis#tab_mapView

Sowjanya, P, Babu, PS & Narasu, ML 2014, 'Phytochemical and Pharmacological potential of Amaranthus viridis L.:-A Review', International Journal of Phytomedicine, vol. 6, no. 3, pp. 322-6.

Alegbejo, JO 2013, 'Nutritional Value and Utilization of Amaranthus (Amaranthus spp.)–A Review', Bayero Journal of Pure and Applied Sciences, vol. 6, no. 1, pp. 136-43.

Note: Updates to come in the next few days.