Our plant of the week: Common butterbur

Petasites hybridus (L.) G.Gaertn., B.Mey. & Scherb.

The common butterbur Petasites hybridus doesn't really look ordinary at all. Rather a bit out of this world? Its pink-red inflorescences with pale, lanceolate stem leaves break through the ground in early spring. They are reminiscent of parasitic plants, e.g. the simultaneously flowering scalewort(Lathraea squamaria L.). The small tubular flowers, which are arranged in baskets typical of the family, offer wild bees plenty of food. In some specimens the anthers are more or less stunted, others only have stunted ovaries. The species is therefore described as incompletely dioecious. After flowering, the stem of the female plants stretches out and becomes up to 1 m long. The wind carries the fruits from this exposed position - similar to the dandelions of the dandelion.

Another representative of the genus in Saxony is the white butterbur (Petasites albus (L.) Gaertn.). Its white flower heads lack any reddish tinge. Later, both sister species develop large, rhubarb-like leaves, to which the scientific genus name refers (ancient Greek 'petasos' = broad-brimmed hat). Then a cut through the leaf stalk helps with identification: in P. hybridus it is hollow, in P. albus it is pithily filled.

The up to 4 cm thick, brownish rhizome of the common butterbur not only serves as a storage organ, it also secures river banks and keeps neighboring plants in check. Its ingredients are quite something: sesquiterpenes have an antispasmodic and pain-relieving effect. Specially isolated butterbur root extracts are therefore considered one of the most effective means of migraine prophylaxis in phytotherapy . Butterbur active ingredients are also used to treat gastrointestinal complaints and hay fever. But beware: all parts of the plant also contain highly toxic, liver-damaging and carcinogenic pyrrolizidine alkaloids! When this was not yet known, folk medicine used the plant as an expectorant for dry coughs and asthma, among other things. In the Middle Ages, the unpleasant smell of its "root" (meaning the rhizome) was supposed to drive away the plague, which was incorporated into the German name.

Petasites hybridus grows in our teaching garden in a shady, slightly damp spot next to other medicinal plants.

(CW 16/26)

Around 10,000 plant species grow in the Botanical Garden of TU Dresden. On this page we regularly present an example of this diversity in more detail. The special features of our scientific plant collection can be seen in many different ways: in amazing adaptations, strange names, interesting uses or even in the extraordinary splendor of their flowers.

You can view previous Plant of the Week articles in the archive.