Urtica lyallii

Watson

Stinging nettle

Urticaceae Edible: Leaves Potential hazards — see below 2,946 iNaturalist observations

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Summary

A hardy perennial nettle reaching 1.2 m, suited to light, medium, and heavy soils with mildly acid to alkaline pH. Adapts to semi-shade or full sun, thriving in moist soil. Dioecious with wind-pollinated flowers from June to August; both male and female plants necessary for seed production.

Description

A herb that keeps growing from year to year. The stems are simple and erect. It grows 1-2 m high. The leaves are opposite and oblong. They can be heart shaped. There are teeth along the edge. There are fine stinging bristles on the stems and leaves. The flowers are small and green. They are in clusters in the axils of leaves.

Edible Uses

Young leaves are cooked and eaten — a highly nutritious food, rich in vitamins and minerals, that works as an excellent spinach substitute and can be added to soups and stews. Harvest only young leaves and wear stout gloves to avoid being stung. Although fresh leaves bear stinging hairs, thorough drying or cooking destroys them entirely. The young shoots are also used to brew nettle beer.

Traditional Uses

The leaves are boiled and eaten. Caution: Leaves sting the skin until boiled.

This uses section is brief — help expand it

Medicinal Uses

The leaves are alterative, antiasthmatic, antidandruff, antispasmodic, diuretic, expectorant, and tonic. An infusion has been used to treat colds, and the plant has been used in a sweat bath to relieve rheumatic-like pains throughout the body. An infusion taken internally has been used to relax muscles during childbirth, and the same preparation applied as a body rub helps treat soreness and stiffness. Fresh leaves rubbed or beaten onto the skin — a practice called urtification — are used for rheumatism. This is thought to work as a counter-irritant by drawing blood to the area to clear rheumatic toxins, while the formic acid in the stings is believed to benefit the affected joints. A decoction of the peeled bark has been used for headaches and nosebleeds, and an infusion of the roots treats intermittent fevers.

Known Hazards

As every other species of Urtica, it has stinging hairs that irritate the skin. This is prevented by cooking it and using the young leaves instead, because older leaves develop cystoliths which act as an irritant to the kidneys.

Distribution

It is a cold temperate plant. It grows in rich soils and on hillsides.

Where It Grows

Alaska, Canada, North America, USA,

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. It is closely related to U. dioica and is sometimes classed as being no more than a sub-species of that species. The Flora of N. America treats this taxon as no more than a synonym for U. gracilis, and also treats that taxon as a sub-species of U. dioica. 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. Dioecious. 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 once large enough to handle, and plant out in summer. Division can be done at almost any point during the growing season — it is very straightforward, and divisions can go directly into their permanent positions.

Other Uses

The stems yield a strong flax-like fibre used for string, cloth, and good-quality paper. It is harvested as the plant begins to die back in early autumn and retted before the fibres are extracted. The leftover plant matter is a useful source of biomass and has been used to manufacture sugar, starch, protein, and ethyl alcohol. Oil from the seeds serves as an illuminant. The plant is an essential ingredient in 'QR' herbal compost activator — a dried, powdered herbal blend added to compost heaps to accelerate bacterial activity and shorten composting time. The leaves are a valuable compost addition and can be soaked in water for 7–21 days to produce a nutritious liquid plant feed that also acts as an insect repellent and foliar feed. The growing plant raises the essential oil content of nearby plants, increasing their resistance to insect pests. Freshly cut stems repel flies and have been kept in food cupboards for this purpose. The plant's juice, or a decoction made by boiling it in a strong salt solution, curdles milk and works as a rennet substitute. The same juice rubbed into leaky wooden tubs coagulates and makes them watertight. A hair wash made from an infusion of the leaves — or a decoction of the roots — is used as a tonic and antidandruff treatment. A permanent green dye comes from a decoction of the leaves and stems; a yellow dye is obtained from the root boiled with alum.

Synonyms

U. dioica lyallii.

References (2)

Heller, C. A., 1962, Wild Edible and Poisonous Plants of Alaska. Univ. of Alaska Extension Service. p 36
Plants for a Future database, The Field, Penpol, Lostwithiel, Cornwall, PL22 0NG, UK. http://www.scs.leeds.ac.uk/pfaf/