Plant 207

Arbutus unedo L. (Ericaceae)


Strawberry tree

Arbutus unedo is a hardy evergreen shrub or tree with shiny leathery leaves and a richly-coloured, peeling bark. It is often grown for its ornamental foliage and bell-like flowers that first open around Halloween. The flowers continue to bloom through the winter months, providing a rare source of nectar for overwintering insects. Its distinctive red, strawberry-like fruit give the species its common name. The fruits, which take one year to mature as they ripen through shades of green-yellow, orange and red, can often be seen on the plant alongside the flowers.

The genus Arbutus comprises about ten species distributed through western North America, western Europe into the Mediterranean region. DNA data indicates that Old and New World Arbutus species are distinct from each other, and are probably not part of the same genus. Arbutus unedo has a curious distribution; it is native to southern Europe and south west Ireland, and is described as a Lusitanian element of the British and Irish floras. This distribution has led to the suggestions that the species once had a larger European range, populations having become isolated as a consequence of past climate change.

Despite the tree's common name, the fruit's similarities to strawberries are only skin deep. They have a rough, outer surface, are tough and not particularly palatable; the species name means 'I eat one'. Fruits often partially ferment on the tree, producing mild intoxicating effects on birds and mammals that eat large quantities of them. The fruit can be used to make jams and beverages, such as the Portuguese liqueur, medronho. However, strawberry tree fruits are not grown commercially, but are foraged and processed on a local scale. The strawberry tree appears on the coat of arms of the Spanish capital Madrid, together with the motto El oso y el madrono (the Bear and the strawberry tree). The image is found across the city on everything from taxis through man-hole covers to civic buildings, but the symbolism is unclear. One explanation has the rampant bear leaning against the tree as symbolising the union between the city authorities and church, which were once divided.

The ornamental varieties of Arbutus unedo that are grown in the United Kingdom today were probably first imported from Ireland during the sixteenth century; it was growing in the Oxford Physic Garden in 1648. By the eighteenth century, Arbutus unedo had become a familiar part of large British gardens.

Further reading

Bean WJ 1970. Trees and Shrubs Hardy in the British Isles. Vol. 1. John Murray.

Hileman LC et al. 2001. Phylogeny and biogeography of the Arbutoideae (Ericaceae): implications for the Madrean-Tethyan hypothesis. Systematic Botany 26: 131-143.

Sarah Lloyd