Urtica cannabina

Scorpion plant, Hemp-leaved nettle, Kentucky Hemp, Halagai

Urticaceae Edible: Leaves, Shoots Potential hazards — see below 2,698 iNaturalist observations

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Summary

Urtica cannabina, the hemp nettle, is a species of flowering plant in the family Urticaceae. It is native to Central Asia, Siberia, Mongolia, and northern and central China, and has been introduced to Ukraine, European Russia, and the Russian Far East. A perennial herb typically 50 to 150 cm (20 to 59 in) tall, it thrives in a wide variety of habitats, including anthropogenically disturbed ones. Attempts are being made in China to cultivate it for its fiber.

Description

A herb that grows in dense tufts. It keeps growing from year to year and has stinging hairs. It grows 1-2 m high. The stems have ridges. The leaves are oval an 4-13 cm long and wide. The leaves are divided like fingers on a hand. There are a few hairs on both surfaces. The flowers are greenish and of separate sexes on the same plant. They are in a group 12 cm long.

Edible Uses

Young leaves are best cooked, making a nutritious spinach substitute or a useful addition to soups and stews. The plant is high in vitamins and minerals. Harvest only young leaves and wear stout gloves to avoid being stung. Fresh leaves carry stinging hairs, but thorough drying or cooking destroys them completely. Nettle beer can be brewed from the young shoots.

Traditional Uses

The young leaves are used as a vegetable or potherb.

This uses section is brief — help expand it

Medicinal Uses

None known.

Known Hazards

The leaves of the plants have stinging hairs, causing irritation to the skin. This action is neutralized by heat so the cooked leaves are perfectly safe and nutritious. However, only young leaves should be used because older leaves develop gritty particles called cystoliths which act as an irritant to the kidneys.

Distribution

It is a temperate plant. In Inner Mongolia.

Where It Grows

Asia, Canada, China, Iran, Manchuria, Middle East, Mongolia, North America, Siberia, Slovenia,

Cultivation

We have very little information on this species and do not know if it will be hardy in Britain, though judging by its native range it should succeed outdoors in most parts of the country. The following notes are based on the general needs of the genus. Prefers a nitrogen-rich soil. The best fibre is produced when plants are grown on deep fertile soils. Usually dioecious, but some plants are monoecious. Male and female plants must be grown if seed is required.

Propagation

Sow seed in spring in a cold frame, barely covering it. Prick seedlings into individual pots when large enough to handle and plant out in summer. Division can be done at almost any time in the growing season — plant divisions straight into their permanent positions.

Other Uses

A strong flax-like fibre from the stems is used to make string, cloth, and good quality paper. It is harvested as the plant begins to die down in early autumn and retted before the fibres are extracted. The following uses are listed for U. dioica but are considered almost certainly applicable here too. Residual plant matter after fibre extraction provides useful biomass for the manufacture of sugar, starch, protein and ethyl alcohol. Seed oil is used as an illuminant. The plant is an essential ingredient of 'QR' herbal compost activator, a dried powdered herbal blend added to compost heaps to accelerate bacterial activity. Leaves make a valuable compost addition and can be soaked for 7–21 days in water to produce a nutritious liquid plant feed that also serves as an insect repellent and foliar feed. The growing plant raises the essential oil content of nearby plants, improving their resistance to insect pests. Flies are repelled by the plant, and freshly cut stems have been kept in food cupboards for this purpose. Plant juice or a decoction boiled in a strong salt solution curdles milk as a rennet substitute; the same juice rubbed into leaky wooden tub seams will coagulate and seal them. Infused leaves make a hair wash used as a tonic and antidandruff treatment. A permanent green dye comes from a decoction of leaves and stems; a yellow dye from the root boiled with alum.

Other Information

It is cultivated.

Notes

It is a widespread weed.

Also Known As

Ha la hai cai, Halagai, Konopljasta kopriva

References (9)

BARANOV,
http://www.botanic-gardens-ljubljana.com/en/plants
Hu, Shiu-ying, 2005, Food Plants of China. The Chinese University Press. p 364
Khasbagan, Hu-Yin Huai, and Sheng-Ji pei, 2000, Wild Plants in the Diet of Athorchin Mongol Herdsmen in Inner Mongolia. Economic Botany 54(4): 528-536
Khasbagan, Yeruhan and Zhao Hui, 2011, Study on Traditional Knowledge of Wild Edible Plants Used by the Mongolians in Xilingol Typical Steppe Area. Plant Diversity and Resources. 33(2): 239-246

Show all 9 references

Plants for a Future database, The Field, Penpol, Lostwithiel, Cornwall, PL22 0NG, UK. http://www.scs.leeds.ac.uk/pfaf/
Sachula, et al, 2020, Wild edible plants collected and consumed by the locals in Daqinggou, Inner Mongolia, China. Journal of Ethnobiology and Ethnomedicine (2020) 16:60
Sp. pl. 2:984. 1753
Zeven, A. C. & de West, J. M. J., 1982, Dictionary of cultivated plants and their regions of diversity. Wageningen. p 84