Common Name: Love Lies Bleeding

General Information

Amaranthus caudatus is a fast-growing, vigorous annual plant with an erect stem that is usually moderately branched. It grows from 50 - 150cm tall, rarely to 250cm, the main stem terminating in a large branched inflorescence[, ].
The plant has a long history of cultivation for its edible leaves and seeds in the Andes. It is often also grown in gardens as an ornamental, Some varieties have red or purple leaves and long, drooping flower stalks[].

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

Range

Tropics

Habitat

A weed of cultivated ground[]. Found in the Andean mountains at elevations between 1,500 - 3,600 metres[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Annual
Height	1.00 m
Pollinators	Wind, Self
Self-fertile	Yes
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Amaranthus caudatus is a plant of the tropics, though it can be cultivated from the tropics to the temperate zones. It grows best in areas where annual daytime temperatures are within the range 21 - 28°c, but can tolerate 7 - 40°c[]. It can be killed by temperatures of 4°c or lower[, ]. It prefers a mean annual rainfall in the range 800 - 2,300mm, but tolerates 250 - 4,200mm[].
Prefers a well-drained fertile soil in a sunny position[, ]. Grows moderately well in poor soils[]. Requires a hot sheltered position if it is to do well[]. Plants are drought resistant though reasonable moisture levels are required for germination and also at pollination[]. Prefers a pH i n the range 5.5 - 7.5, tolerating 4.3 - 8.5[].Some forms can tolerate mild salinity[]. It is likely that they will also tolerate acid soils and aluminium toxicity[].
A weed in many parts of the tropics.
This species is cultivated for its edible seed and leaves in the Andes and various other parts of S. America[, , ]. It probably arose through cultivation from A. Quitensis. There are some named varieties[]. Plants take 4 - 6 months from sowing to harvesting the seed, but up to 10 months in some Andean highland regions[]. Yields from 1 - 3 tonnes per hectare are common, 5 tonnes has been achieved and research sites have produced the equivalent of 6 tonnes per hectare[]. The seed is usually harvested just before maturity otherwise some of the seed will be lost during harvesting[]. Plants usually have downward facing seed heads but varieties have been developed with upward facing heads that can be harvested mechanically[].
This species is sensitive to day-length most cultivars are short-day and have not done well in northern latitudes, but there are some varieties that flower at day-lengths up to 16 hours[].
Plants are particularly susceptible to attacks by leaf-chewing insects[].
Plants should not be given inorganic fertilizers, see notes above on toxicity.
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 - raw or cooked as a spinach or added to soups etc[, , , , , ]. The mild flavoured leaves are rich in vitamins and minerals[, ]. A good source of vitamins A & C, iron and calcium[].

Seed - cooked[, , , ]. Very small but easy to harvest and very nutritious, individual plants can bear up to 100, 000 seeds[]. It is eaten cooked or ground into a powder and used in baking[, , ]. The seed can also be popped in much the same way as popcorn[, ]. 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[]. The seed is very nutritious and contains 13 - 18% of a very high quality protein that is rich in the amino acid lysine[]. It contains 4.8 - 8.1% oil[] and also contains good quantities of calcium, phosphorus, iron, potassium, zinc, vitamin E and the vitamin B complex[].

A red food colouring called 'betalaina' is obtained from red cultivars[].

Medicinal

The plant is astringent, anthelmintic and diuretic[, ]. It is used in the treatment of stranguary and is applied externally to scrofulous sores[].

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[].