A perennial, but of short duration, generally abundant on meadow land of a light sandy nature, where it produces abundant blossom, forming an excellent mowing crop. Not of great value as a bee plant - the bees not working it for so long as they will the white variety.
Several stems 1 to 2 feet high, arising from the one root, slightly hairy; leaves ternate, leaflets ovate, entire, nearly smooth, ending in long point often lighter coloured in centre, flowers red to purple, fragrant, in dense terminal ovoid or globular heads.
Trifolium pratense L. (Leguminosae).
Synonyms and Part Used
Cow Clover, Meadow Clover, Purple Clover, Trefoil.
Arabinose, glucose, glucuronic acid, rhamnose, xylose (following hydrolysis of saponin glycosides); polysaccharide (a galactoglucomannan).
Biochanin A, daidzein, formononetin, genistein, pratensin, trifoside, calycosine galactoside and pectolinarin.
Isorhamnetin, kaempferol, quercetin, and their glycosides.
Soyasapogenols B–F (C–F artefacts) and carbohydrates (see above) yielded by acid hydrolysis.
Coumaric acid, phaseolic acid, salicylic acid, trans- and cis-clovamide (L-dopa conjugated with trans- and cis-caffeic acids), resin, volatile oil (containing furfural),fats, vitamins and minerals. Cyanogenetic glycosides have been documented for a related species, Trifolium repens.
Red clover is listed by the Council of Europe as a natural source of food flavouring (category N2). This category indicates that it can be added to foodstuffs in small quantities, with a possible limitation of an active principle (as yet unspecified) in the final product.
Red clover is stated to act as a dermatological agent, and to possess mildly antispasmodic and expectorant properties. Tannins are known to possess astringent properties. Traditionally red clover has been used for chronic skin disease, whooping cough, and specifically for eczema and psoriasis.
Dried flowerhead :4 g or by infusion three times daily.
Liquid extract : 1.5–3.0 mL (1 : 1 in 25% alcohol) three times daily.
Tincture : 1–2 mL (1 : 10 in 45% alcohol) three times daily.
In vitro and animal studies
Biochanin A, formononetin, and genistein (isoflavones) are known to possess oestrogenic properties.The saponin constituents are reported to lack any haemolytic or fungistatic activity. A possible chemoprotective effect has been documented for biochanin A, which has been reported to inhibit carcinogenic activity in cell culture.
Urticarial reactions have been documented.Infertility and growth disorders have been reported in grazing animals.These effects have been attributed to the oestrogenic isoflavone constituents, in particular to formononetin.
In view of the oestrogenic constituents, excessive ingestion should be avoided. Large doses may interfere with anticoagulant and hormonal therapies (coumarin and isoflavonoid constituents).
Pregnancy and lactation
In view of the oestrogenic components the use of red clover during pregnancy and lactation should be avoided.
The chemistry of red clover is well documented. Limited information is available on the pharmacological properties and no documented scientific evidence was found to justify the herbal uses. Reported oestrogenic side–effects in grazing animals have been attributed to the isoflavone constituents. Little toxicity data are available for red clover. In view of this and the isoflavone and coumarin components, excessive ingestion should be avoided.