Aristolochia clematitis, (European) Birthwort, is a twining herbaceous

Herbaceous

A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...

 plant in the Aristolochiaceae

Aristolochiaceae

The Aristolochiaceae, or the Birthwort family, are a family of flowering plants with 7 genera and about 400 species belonging to the order Piperales...

 family, which is native to Europe. The leaves are heart shaped and the flowers are pale yellow and tubular in form. The plant seeks light by ascending the stems of surrounding plants.

Medicinal problems

It was formerly used as a medicinal plant (though poisonous) and is now occasionally found established outside of its native range as a relic of cultivation. A recent study suggests that it is the cause for thousands of kidney failures in Romania, Bulgaria, Serbia and Croatia where the plant is unintentionally consumed through flour. This was discovered after a clinic for obesity in Belgium used aristolochic acid, a component of this plant, as a diuretic. After a few months, some of the patients experienced kidney carcinoma and kidney failure.