Oxfordshire Flora Group


Aristolochia clematitis, Birthwort

This web page is adapted from the Fritillary paper by Sheila Ottway,, which reports on her ten years of monitoring the plant.

Aristolochia clematitis, Birthwort, Godstow Abbey, Oxford.
Photo by Frances Watkins

Oxfordshire site

Birthwort Aristolochia clematitis occurs at the site of the ruins of the nunnery at Godstow, near Oxford, where it has been monitored since 1996. Godstow is situated about 4 km to the north of the city of Oxford. Birthwort must have been planted in a herb garden within the Abbey precincts, and has evidently continued to grow on the site ever since.

Birthwort is a perennial plant that sends up fresh shoots every year. Over the years the number of shoots counted (not necessarily flowering) has ranged from 139 to 535. It should be noted, however, that counting the shoots is not easy as they grow among scrub and stinging nettles. Moreover, the plant is rhizomatous so it is not at all clear how many plants these counts represent.

Other UK sites

While it is widely naturalized in many parts of Continental Europe, Birthwort has a limited distribution in the British Isles: it is to be found at about 15 sites in lowland England, and one in South Wales. The date of introduction is unknown, but it was recorded in the wild from Cambridgeshire in 1685.

History of Birthwort

Birthwort is not a native species in the British Isles. It was introduced from Continental Europe, at some time in the Middle Ages, as a plant for medicinal purposes. The active substance was derived from its rhizomes (i.e. swollen roots). It was grown in medieval herb gardens, especially those of monastic establishments.

Birthwort was used during the Middle Ages and Early Modern period as a herbal remedy, mainly to aid women in childbirth. It was also used to induce abortions. This medicinal use of Birthwort was connected with the supposed morphological resemblance between its funnel-shaped yellow flowers and the human uterus. Although this is clearly a fanciful connection, Birthwort certainly does have pharmacological properties, and these were already well recognized by the Ancient Greeks and Romans and by Arab physicians of the medieval period. It is now known, however, that Birthwort can be extremely toxic, and its use as herbal treatment may lead to kidney failure.

Birthwort in bloom (in foreground) growing close to the E-W running wall at the site of Godstow Abbey, June 2011.
Photo by Sheila Ottway.

Further reading

  • Scarborough, J. 2001. Ancient Medicinal Uses of Aristolochia: Birthwort’s Tradition and Toxicity. Pharmacy in History, 53:1, 3-21.