Common Name: Rough-fruit Water-hemp

General Information

Amaranthus tuberculatus is an erect to sometimes ascending or more rarely prostrate, usually branched annual plant growing up to 2 metres tall, occasionally to 3 metres[].
The plant is harvested from the wild for local use as a food.
Amaranthus tuberculatus has spread from its native range in northern North America and is considered a major weed of agricultural fields and other disturbed areas in 40 US states. In the mid-western USA it has become increasingly difficult to control since the advent of the 21st century due to a persistent seedbank and the development of resistance to certain herbicides. The seed is a known contaminant of soyabean seed and other grains, and has been accidentally introduced and become naturalized in parts of West Asia and Europe - it is considered to be 'Invasive' in Italy. Once introduced, the plant appears to thrive along water courses and rivers, its high reproductive capacity allowing it to spread rapidly with resulting adverse ecological effects on the native riparian herbaceous vegetation, for example along the banks of the River Po in Italy. Potential spread to other areas should be considered likely[].

Known Hazards

None known

Botanical References

Range

N. America - Manitoba to Quebec, south to New Mexico, Texas and Georgia

Habitat

Wet areas, such as margins of rivers, ponds, marshes, lakes, and creeks, disturbed habitats, such as agricultural fields, roadsides, and railroads; at elevations up to 1,000 metres[].

Properties

Weed Potential	Yes
Edibility Rating
Habit	Annual
Height	1.50 m
Cultivation Status	Wild

Cultivation Details

Species in this genus generally prefer a well-drained fertile soil somewhat on the light side, and a sunny position[, ].
A dioecious species, both male and female forms of the plant need to be grown if fruit and seed are required[].

Edible Uses

Leaves - cooked. Eaten as a vegetable[].

Medicinal

None known

Other Uses

None known

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[]. A minimum soil temperature of 10°c is required for germination, germination is better at temperatures above 20°c[]. A drop in temperature overnight aids germination[].
Cuttings of growing plants root easily[].