The plant was named Trifolium pratense by Carolus Linnaeus in 1753. Pratense is Latin for "found in meadows".

There are seven varieties :

• Trifolium pratense pratense - widespread

• Trifolium pratense americanum - southeastern Europe (despite the name)

• Trifolium pratense frigidum - mountains of central and southern Europe ( Pyrenees, Alps, Balkans)

• Trifolium pratense maritimum - southern Baltic Sea coast.

• Trifolium pratense parviflorum - Europe.

• Trifolium pratense sativum - Mediterranean region, robust-growing, with hairless or nearly hairless foliage

• Trifolium pratense villosum - Alps, densely hairy foliage

Red clover is subject to bacterial as well as fungal diseases. Other problems include parasitic nematodes (roundworms) and viruses.

It is widely grown as a fodder crop, valued for its nitrogen fixation, which increases soil fertility. For these reasons it is used as a green manure crop. Several cultivar groups have been selected for agricultural use, mostly derived from var. sativum . It has become naturalised in many temperate areas, including the Americas and Australasia as an escape from cultivation.

Red clover contains isoflavones ( estrogen-like compounds ) which can mimic the effect of endogenous estrogen. The use of red clover to relieve menopausal symptoms has been shown to be sometimes ineffective, but safe.

Traditionally, red clover has been administered to help restore irregular menses and to balance the acid-alkaline level of the vagina to promote conception.

The isoflavones (like irilone and pratensein) from red clover have been used to treat the symptoms of menopause. It has also been reported that red clover has been used for a variety of medicinal purposes, such as bronchitis, burns, cancers, ulcers, sedation, asthma, and syphilis.

It is an ingredient in eight-herb essiac tea.

Due to its activity on estrogen receptors, it is contraindicated in people with a history of breast cancer, endometriosis, ovarian cancer, uterine cancer, uterine fibroids, or other estrogen-sensitive conditions but others have suggested that the high isoflavone content counteracts this and even provides benefits in these conditions.

Due to its coumarin derivatives, it should be used in caution in individuals with coagulation disorders or currently undergoing anticoagulation therapy.

It is metabolized by CYP3A4 and therefore caution should be used when taking it with other drugs using this metabolism pathway.

It is the national flower of Denmark and the state flower of Vermont.

• Green manure

• Flora Europaea: Trifolium pratense

• Germplasm Resources Information Network: Trifolium pratense

• Red-clover seed production in the Intermountain States hosted by the UNT Government Documents Department

pratense