An interesting plant in the garden: Winter Heliotrope
by Isla Browning
Winter Heliotrope (Petasites pyrenaicus) is growing in the garden and outside the walls. It
has recently been spreading inside the garden by the east and west wall. It was previously
named Petasites fragrans, which is perhaps more apt in view of the fact that the flowers are
strongly almond or vanilla scented. Research at St Andrews University has shown that the
chemical causing the smell repels ants!
The plant is native to Southern Europe and North Africa. It was introduced to the UK as a
garden ornamental around 1806 and recorded in the wild by 1835. It is now common in
England, but less so in Scotland. It is likely that on occasions it was introduced as an early
source of nectar and pollen for honeybees. Apparently, in Scandinavia, it was planted near
beehives, so that the bees would benefit from the nectar and pollen before most other plants
were in flower. I wonder if the plant was introduced to Granton Castle area for this purpose.
The photo shows a bee on a flower in the garden.
Winter Heliotrope is dioecious (male and female flowers on separate plants). In the UK and
Ireland plants are reported only to have male flowers. If you look closely at the florets, you
can see that pollen is produced within pink coloured stamens. However, they also have some
non-functional (vestigial) female parts. I wonder if the plant has been monoecious in the
past? It is a mystery! No seeds are produced, and it spreads by means of rhizomes in the soil.
It is highly invasive. Apparently, it can burrow deeply underground. Has it managed to creep
under the garden walls?