Category: Medicines - plant based
Introduction and description
Geum urbanum, also known as wood avens, herb Bennet, and colewort, is a perennial plant in the rose family (Rosaceae), which grows in shady places (such as woodland edges and near hedgerows) in Europe and the Middle East.
Geum urbanum hybridises fairly regularly with Geum rivale (water avens), as they are closely related and occur together.
Avens had many other names in the fourteenth century, such as Assarabaccara, Pesleporis, or Harefoot, and Minarta. It was called 'the Blessed Herb' (Herba benedicta), of which a common name still extant - Herb Bennet - is a corruption. “Dr. Prior (Popular Names of English Plants) considers the original name to have probably been St . Benedict's Herb, that name being assigned to such as were supposed to be antidotes”.
In folklore, wood avens is credited with the power to drive away evil spirits, and to protect against rabid dogs and venomous snakes. This may well mean it is good against toxins and is an antiviral but as yet we have no detailed analysis to back this up.
Astrologically, it was said to be ‘ruled by Jupiter’.
Stems – Wood avens has thin, nearly upright, wiry stems, slightly branched, from 1 to 2 feet in height, of a reddish brown on one side.
Leaves vary considerably in form, according to their position. The radical leaves are borne on long, channelled foot-stalks, and are interruptedly pinnate, the large terminal leaflet being wedge-shaped and the intermediate pairs of leaflets being very small. The upper leaves on the stem are made up of three long, narrow leaflets: those lower on the stems have the three leaflets round and full. The stem-leaves are placed alternately and have at their base two stipules (leaf-like members that in many plants occur at the junction of the base of the leaf with the stem). Those of the Avens are very large, about an inch broad and long, rounded in form and coarsely toothed and lobed. All the leaves are of a deep green colour, more or less covered with spreading hairs, their margins toothed.
The rhizomes are 1 to 2 inches long terminating abruptly, hard and rough with many light brown fibrous roots. The botanical name, Geum, originated from the Greek geno, to yield an agreeable fragrance, because, when freshly dug up, the root has a clove-like aroma. This gives rise to another name, Radix caryophylata, or Clove Root.
The flowers, rather small for the size of the plant, are on solitary, terminal stalks. The hermaphrodite flowers are scented and pollinated by bees. The corolla is composed of five roundish, spreading, yellow petals, the calyx cleft into ten segments - five large and five small. The flowers, which are in bloom all the summer and autumn, often as late as December, are less conspicuous than the round fruitheads, which succeed them.
The fruits have burrs, which are used for dispersal by getting caught in the fur of rabbits and other animals and which are formed of a mass of dark crimson achenes, each terminating in an awn, the end of which is curved into a hook.
As Avens does not occur in the USA, there is, sadly, no detailed analysis of its constituents from Dr Duke’s phytochemical database [which is based in the USA]. Sadly, because this little plant has a long history of use in herbal medicine and a rich folkloric history. The best paper we could find on the chemical constituents is the following, but you will need to go to PubMed to get the full list
A study of the composition of essential oils from aerial and underground parts of Geum rivale L. and Geum urbanum L. growing in Poland led to the identification of 130 compounds. The main compound of the essential oil from underground parts of G. urbanum was eugenol (69.2%), whereas cis-myrtanal (53.3%) was the major constituent of the essential oil from roots of G. rivale. The essential oils from aerial parts of the plants contained large amounts of aliphatic compounds with (Z)-3-hexenol (38.4%) being the dominant constituent of the essential oil from aerial parts of G. urbanum and 1-octen-3-ol (33.9%) from G. rivale. PMID: 23738465
The root was once used as a spice in soups and also for flavouring ale, as such it was possibly used in herbal ales. In medieval days the wines and beers were the principal means of both preserving herbs over the winter and providing them as medicines – tonic ales and wines.
The Augsburg Ale is said to owe its peculiar flavour to the addition of a small bag of Avens in each cask. The fresh root imparts a pleasant clove-like flavour to the liquor, preserves it from turning sour, and adds to its wholesome properties.
The root also contains tannins, which should help in any wines and gives it useful medicinal properties as a chelator. And sugars meaning it would help fermentation. Mrs Grieve even provides us with a handy recipe, though it needs no fermentation...
Mrs Grieves’ Avena tonic cordial
Avens root 1 1/2 OZ.;
Angelica root, bruised, and Tormentil root bruised, of each 1 OZ.;
Raisins, stoned, 2 OZ.;
French brandy, 2 pints.
Macerate for a month in a warm place.
Filter then through paper. Dose, 1/2 oz.
The infusion is considered an excellent cordial at the commencement of chills and catarrh, cutting short the paroxysm, and the continued use of it has restorative power in weakness, debility, etc.
Completely inebriated but healthy [chortle].
In most of the herbals it was the root that was used, but in olden days it was dried. It loses much of its odour and medicinal potency in drying, so in olden days had to be dried with great care, and gradually, then sliced and powdered as required. This is thus one plant which would benefit from having its roots preserved in such a way that all its constituents were still present.
There is the possibility that semi-dormant roots are easier to dry and indeed in olden days the roots were dug up in spring; some of the old physicians were so particular on this point that the 25th March was fixed for procuring the root (and it was specified that the soil should be dry). At this time the root was said to be ‘most fragrant’.
One use for the root was as a ‘styptic’. A styptic checks bleeding by contracting the tissues or blood vessels capable of causing bleeding to stop when it is applied to a wound.
It was also used to promote sweating and help fevers break. Sweating is one of the body’s ways of expelling pathogens – washed away in sweat. Fever also helps kills some pathogens particularly viruses.
And again, another traditional use was as a ‘stomachic’. Stomachic is a historic term for a medicine that serves to tone the stomach, improving its function and increasing appetite.
There are tantalising hints throughout many descriptions that it is an antibacterial, antiviral, and an antiparasitic – anthelmintic - and possibly quite a strong one.
A cordial against the plague was made by boiling the roots in wine. Gerard recommends a 'decoction made in wine against stomach ills.' On account of its stomachic properties, chewing of the root was recommended for foul breath.
And again this time Culpepper
The root in the spring-time steeped in wine doth give it a delicate flavour and taste and being drunk fasting every morning comforteth the heart and is a good preservative against the plague or any other poison. It is very safe and is fit to be kept in every body's house.'
Ignoring the ‘It is very safe’ bit, it is clear this herb deserves much more analytical attention.
There is excellent research work being undertaken in the old eastern block countries on constituents and properties but this is all relatively new. The answer is, I think to keep a close watch on PubMed for new findings.
Paracelsus suggested its use against liver disease, catarrh and stomach upsets. Geum urbanum herb and roots have been used in traditional Austrian medicine as a tea for the treatment of rheumatism, gout, infections, and fever. Modern herbalists use it to treat diarrhoea, heart disease, halitosis and mouth ulcers. All of these are consistent with it being an antibiotic, antiviral and possibly an antifungal. The next step is to find out which pathogens it attacks.
References and further reading
- Vicianose from the root of Geum urbanum - Psenák M, Jindra A, Stano J, Suchý V. Planta Med. 1972 Aug;22(1):93-6. PMID: 5083254
- Biochemical study on Geum urbanum. Psenák M, Jindra A, Kovács P, Dulovcová H. Planta Med. 1970 Nov;19(2):154-9. PMID: 5501304
- [Sugar in wood avens (Geum urbanum)]. Psenák M, Woitowitz D, Kovács P, Jindra A. Cesk Farm. 1965 Oct;14(8):397-401. Czech. PMID: 5853280
- [Anatomical structure of Geum urbanum and Geum rivale and localization of tannins]. BLINOVA KF. Aptechn Delo. 1954 Mar-Apr;3(2):30-5. Undetermined Language. PMID: 13159200
- Avens - The Healing power of herbs – Ceres Esplan 019741
- Inhibitory potential of some Romanian medicinal plants against enzymes linked to neurodegenerative diseases and their antioxidant activity 019739
- Mrs Grieve on Avens 019740
- Role of human gut microbiota metabolism in the anti-inflammatory effect of traditionally used ellagitannin-rich plant materials 019742