Prickly Comfrey
Symphytum asperum
Family: Boraginaceae
What it is like
Symphytum asperum is a PERENNIAL growing to 1.5 m (5ft) by 0.6 m (2ft in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 5. It is in flower from May to June, and the seeds ripen from June to July. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and can grow in heavy clay soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.
Height (m): 1.5
Where it is found
Waste places in Britain.
Europe to W. Asia. Occasionally naturalized in Britain.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 3
The following reports are for S. officinale, they are said to also apply to this species. Young leaves - cooked or raw. The leaf is hairy and the texture is mucilaginous. It may be full of minerals but it is not pleasant eating for most tastes. It can be chopped up finely and added to salads, in this way the hairiness is not so obvious. Young shoots can be used as an asparagus substitute. The blanched stalks are used. Older leaves can be dried and used as a tea. The peeled roots are cut up and added to soups. A tea is made from the dried leaves and roots. The roasted roots are used with dandelion and chicory roots for making coffee.
Gum: can be chewed as a chewing gum or can often be used as a sweetener or thickening agent in foods.
Tea: the various herb teas that can be used in place of tea, plus the genuine article.
Medicine
Rating: 2
The leaves are anodyne, mildly astringent, demulcent, emollient, expectorant, haemostatic, refrigerant and vulnerary. They are used as an external poultice in the treatment of cuts, bruises and sprains. Internally, they are used as a tea in the treatment of chest complaints. The plant contains a substance called 'allantoin', a cell proliferant that speeds up the healing process. The leaves are harvested in the summer and can be used fresh or dried.
Anodyne: Relieves pain, it is milder than an analgesic.
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.
Emollient: Softens the skin, causing warmth and moisture.
Expectorant: Clears phlegm from the chest by inducing coughing.
Haemostatic: Controls internal bleeding.
Refrigerant: Cools the body.
Vulnerary: Promotes the healing of wounds.
Other
Rating: 0
The following reports are for S. officinale, they are said to also apply to this species. The plant grows very quickly, producing a lot of bulk. It is tolerant of being cut several times a year and can be used to provide 'instant compost' for crops such as potatoes. Simply layer the wilted leaves at the bottom of the potato trench or apply them as a mulch in no-dig gardens. A liquid feed can be obtained by soaking the leaves in a small amount of water for a week, excellent for potassium demanding crops such as tomatoes. The leaves are also a very valuable addition to the compost heap. A gum obtained from the roots was at one time used in the treatment of wool before it was spun.
Biomass: Provides a large quantity of plant material that can be converted into fuel etc.
Compost: Plants used for activating compost heaps, providing biomass for composting, using as instant compost etc.
Gum: Gums have a wide range of uses, especially as stabilizers, emulsifiers, thickening agents, adhesives etc.
How it is grown
Tolerates most soils and situations but prefers a moist soil and some shade. Grows well in heavy clay soils. Best grown in an open sunny site in a deep rich soil if it is being grown for compost material. Plants can be invasive, often spreading freely by means of self-sown seed. They are also very difficult to remove, the root system is very deep and even small fragments of root left in the soil can produce new plants.
Propagating it: Seed - sow spring or autumn in a cold frame. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. If you have sufficient seed you can try an outdoor sowing in situ in the spring. Division succeeds at almost any time of the year. Simply use a spade to chop off the top 7cm of root just below the soil level. The original root will regrow and you will have a number of root tops, each of which will make a new plant. These can either be potted up or planted out straight into their permanent positions.
Best place to grow: Woodland Garden Sunny Edge; Dappled Shade; Shady Edge; Cultivated Beds;
Habit: Perennial
Hardiness: 4-8
Growth: Fast
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Moist
Things to keep in mind
No reports of toxicity have been seen for this species, but the following reports have been seen for S. officinale. This plant contains small quantities of a toxic alkaloid which can have a cumulative effect upon the liver. Largest concentrations are found in the roots, leaves contain higher quantities of the alkaloid as they grow older and young leaves contain almost none. Most people would have to consume very large quantities of the plant in order to do any harm, though anyone with liver problems should obviously be more cautious. In general, the health-promoting properties of the plant probably far outweigh any possible disbenefits, especially if only the younger leaves are used.