Alkanet, Alkanna
Alkanna tinctoria

Family: Boraginaceae

What it is like

Alkanna tinctoria is a PERENNIAL growing to 0.2 m (0ft 8in) by 0.3 m (1ft). It is in flower in June. The species is hermaphrodite (has both male and female organs). Suitable for: light (sandy) and medium (loamy) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers dry or moist soil and can tolerate drought. The plant can tolerate maritime exposure.

Height (m): 0.2

Where it is found

Maritime sands, uncultivated ground, calcareous soils and pine forests.

S. Europe.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 1

Used as a vegetable. No further details are given. A red dye obtained from the roots is used as a food colouring.

Colouring: edible dyes

Medicine

Rating: 2

The root is antibacterial, antipruritic, astringent and vulnerary.It is used externally in the treatment of varicose veins, indolent ulcers, bed sores and itching rashes. Used internally to treat cough and bronchial catarrh (see known hazards above). Used in the treatment of skin wounds and diarrhoea .The root is harvested in the autumn and can be dried for later use. All plant parts are demulcent and expectorant .

Antibacterial: Kills bacteria.

Antidiarrhoeal: Provides symptomatic relief for diarrhoea. Also see Astringent.

Antipruritic: Treats itching of the skin.

Astringent: Produces contraction in living tissue, reducing the flow of secretions and discharges of blood, mucus, diarrhoea etc.

Demulcent: Soothes, lubricates and softens irritated tissues, especially the mucous membranes.

Expectorant: Clears phlegm from the chest by inducing coughing.

Vulnerary: Promotes the healing of wounds.

Other

Rating: 2

A red dye is obtained from the roots, it is used by pharmacists as well as in perfumes and to stain wood or marble. The dye is also used in thermometers and as a litmus to test for acids and alkalines. It can make wood look like rosewood or mahogany.

Dye: Plants that provide dyes.

Litmus: Used for testing whether a substance is acid or alkaline.

How it is grown

Prefers a well-drained sandy or loamy soil in sun or partial shade. Dislikes acid soils but thrives in alkaline soils. A very drought tolerant plant when established, succeeding in a hot dry position, it is a useful plant for dry sandy or alkaline soils. Plants are hardy to about -10°c. This species is occasionally cultivated as a dye plant. One report says that it is cultivated for its seed.

Propagating it: Seed - sow spring in a cold frame. When large enough to handle, prick the seedlings out into individual pots and plant them out in the summer. Division in spring. Fairly easy, they can be planted straight out into their permanent positions if required. Basal cuttings of new growth in late spring. Harvest the young shoots when they are about 10 - 15cm long and pot them up into individual pots in a lightly shaded position in a greenhouse. They should root well within a few weeks and can be planted out in the summer. Root cuttings in late winter.

Best place to grow: Woodland Garden Dappled Shade; Cultivated Beds;

Habit: Perennial

Hardiness: 0-0

Growth:

Soil: Light (sandy), medium

Shade: Semi-shade, no shade

Moisture: Dry, moist

Things to keep in mind

Hepatotoxicity (liver toxicity) and carcinogenicity . Many members of this plant family contain a liver-damaging alkaloid and so internal usage is inadvisable.

Its other names

Local names

Synonyms

Anchusa tinctoria.