Common Name: Green Amaranth

General Information

Amaranthus hybridus is an erect annual plant with a stem that can be much-branched to nearly free of branches; it usually grows 30 - 200cm tall, occasionally to 250cm[].
The plant has a long history of cultivation as a food crop and is still sometimes cultivated on a small scale for its edible leaves and seeds.
A prolific producer of seed, the plant has often escaped from cultivation and become naturalised as a weed of disturbed and cultivated ground[].

Known Hazards

No members of this genus are known to be poisonous, but when grown on nitrogen-rich soils they are known to concentrate nitrates in the leaves. This is especially noticeable on land where chemical fertilizers are used. Nitrates are implicated in stomach cancers, blue babies and some other health problems. It is inadvisable, therefore, to eat this plant if it is grown inorganically.

Botanical References

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Range

Widespread in the tropics, originally from the Americas. Naturalized in Europe[].

Habitat

Of uncertain origin, it grows wild in cultivated fields and waste places[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Annual
Height	0.60 m
Pollinators	Wind, Self
Self-fertile	Yes
Cultivation Status	Cultivated, Wild

Cultivation Details

A plant originally from the tropics, it is widely cultivated from the temperate zone through to most tropical areas, where it is found at elevations up to 1,300 metres[]. It grows best in areas where annual daytime temperatures are within the range 12 - 30°c, but can tolerate 8 - 35°c[]. It can be killed by temperatures of 4°c or lower[]. It prefers a mean annual rainfall in the range 400 - 600mm, but tolerates 300 - 700mm[]. These rainfall figures seem very low - the plant can be grown in areas of much higher rainfall than this[].
Prefers a well-drained fertile soil in a sunny position[]. Requires a hot sheltered position if it is to do well[]. Prefers a pH in the range 6.5 - 7.5, tolerating 6 - 8.5[].
Plants are particularly susceptible to attacks by leaf-chewing insects[].
Plants should not be given inorganic fertilizers, see notes above on toxicity.
Cultivated as a food crop in India[, ], there are many named forms[]. This species has the potential, through crossbreeding, of imparting early maturity to the white seeded grain amaranths[].
Most if not all members of this genus photosynthesize by a more efficient method than most plants. Called the 'C4 carbon-fixation pathway', this process is particularly efficient at high temperatures, in bright sunlight and under dry conditions[].

Edible Uses

Leaves and young seedlings - cooked as a spinach, added to soups etc or eaten raw[, , , , ]. The nutritious leaves have a mild flavour[].

Seed - raw or cooked[, , , ]. Used as a cereal substitute, the seed is usually ground into a flour for use in porridges, bread etc. It is rather small, about 1mm in diameter[], but is easy to harvest and very nutritious[]. It contains 12 - 15% crude protein, which is relatively high in lysine, and 4.8 - 8.1% oil[]. The seed can be cooked whole, and becomes very gelatinous like this, but it is rather difficult to crush all of the small seeds in the mouth and thus some of the seed will pass right through the digestive system without being assimilated[].

A red edible dye is obtained from the inflorescence, it is used in S. America for colouring ceremonial maize dishes[].

Medicinal

A tea made from the leaves is astringent[, ]. It is used in the treatment of intestinal bleeding, diarrhoea, excessive menstruation etc[, ].

Other Uses

Yellow and green dyes can be obtained from the whole plant[].

Propagation

Seed - sow late spring in situ. An earlier sowing can be made in a greenhouse and the plants put out after the last expected frosts. Germination is usually rapid and good if the soil is warm[], but poor germination rates are experienced in cool or cold soils[]. A drop in temperature overnight aids germination[].
Cuttings of growing plants root easily[].