Butterbur, Pestilence wort

Petasites hybridus

Physical Characteristics

Petasites hybridus is a PERENNIAL growing to 1 m (3ft 3in) by 3 m (9ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 4. It is in leaf from April to December, in flower from March to May. The species is dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required). and is pollinated by Insects. The plant is not self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in full shade (deep woodland) semi-shade (light woodland) or no shade. It prefers moist or wet soil.

Distribution

Europe, including Britain, from Scandanavia south and east to Spain, north and west Asia.

Habitats

Woodland Garden Dappled Shade; Shady Edge; not Deep Shade; Meadow; Bog Garden;

Edible Uses

None known

Medicinal Uses

Analgesic Antispasmodic Appetizer Cardiotonic Diaphoretic Diuretic Homeopathy Urinary Butterbur is widely considered to be an effective cough remedy and recent experiments have shown it to have remarkable antispasmodic and pain-relieving properties[244]. It acts specifically on the bile ducts, stomach and duodenum[254]. The plant contains pyrrolizidine alkaloids, in isolation these are toxic to the liver[254]. The root and the leaves are analgesic, antispasmodic, cardiotonic, diaphoretic and diuretic[4, 9]. A decoction is taken as a remedy for various respiratory problems such as asthma, colds, bronchitis and whooping cough and also other complaints such as fevers and urinary complaints[4, 254]. It is also very effective in the treatment of gastrointestinal complaints and biliary dyskinesia[244, 254]. Externally it can be used as a poultice to speed the healing of wounds and skin eruptions[254]. The leaves are harvested in early summer, the root in late summer to autumn. Both can be dried for later use[9]. Because the plant contains potentially toxic alkaloids its internal use cannot be recommended[254]. A homeopathic remedy is made from the roots[4]. It is used in the treatment of severe and obstinate neuralgia[4]. Petasites hybridus (commonly known as butterbur) contains pyrrolizidine alkaloids (PAs), which can be hazardous. These compounds are toxic to the liver and can cause serious side effects, including liver damage, hepatic veno-occlusive disease, and even an increased risk of cancer with prolonged exposure. Because of this, raw or unprocessed butterbur extracts are unsafe for internal use. Commercial butterbur preparations that are marketed for migraines, hay fever, or asthma are often labeled “PA-free”, meaning the pyrrolizidine alkaloids have been removed through processing. Only these PA-free extracts are considered safe for short-term use, and even then, they should be taken with medical guidance.

Known Hazards

Never use unprocessed butterbur (teas, leaves, roots, or homemade extracts), since the pyrrolizidine alkaloids can be highly toxic.