Petasites hybridus
- Overview
- Images
- Identify
- Biology
- Taxonomy
- Occurrence
- Specimen
- Invasive alien species
Description
Butterburs are tall perennials of the subfamily Asteroideae. They are dioecious, which means that there are separate male and female individuals. Butterburs have flowering stems that emerge in late spring, and grow taller at the fruition stage. At the final stages of flowering, green rosette leaves emerge from the ground. They grow over the summer to become up to one metre wide. Butterburs spread vegetatively from rhizome fragments.Common butterbur usually has deep purple flowers. In Finland, the plants are almost exclusively male. Japanese butterbur (P. japonicus ssp. giganteus) has yellowish flowers and only male plants exist in Finland, and throughout the Nordic countries. None of the species produce seeds in Finland.
The map represents observations of this taxon, but it may not be used as a distribution map.
- Total squares
- etelänruttojuuri (Finnish)
- pestskråp (Swedish)
- TNV - alien, new, resident
- 3 - spreading in the wild; completely of cultivated origin
Establishment | Established |
---|
Finland’s National Strategy on Invasive Alien Species (GR 2012) ?
- 2019 NA – Not Applicable
- 2010 NA – Not Applicable
- Arto Kurtto
- Vascular plants