The strawberry tree flowers and ripens last year's fruit at the same time
Its red berries look like strawberries but the tree belongs to the heather family. Arbutus unedo takes about a year to ripen each crop, so every autumn it carries white bell flowers and ripe fruit together. Its species name may record Pliny the Elder saying he would eat only one.
Arbutus unedo is an evergreen shrub or small tree, usually 4 to 7 metres tall, native to the Mediterranean Basin and Western Europe. Linnaeus named it in his 1753 Species Plantarum. Its rough, round berries grow up to 20 mm across and sweeten as they redden. The name unedo is traced to Pliny, whose supposed remark, I eat only one, leaves open whether the fruit was too good to share or too dull for a second.
Its range has a puzzle. Besides the Mediterranean, relict populations grow in south-western Ireland, making it a classic member of the Lusitanian flora, plants shared by Iberia and Ireland but largely missing from Britain. Recent genetic work suggests it may not be truly native to Ireland at all but introduced by people during the Chalcolithic, the copper age. Genetically it is closer to Mediterranean relatives such as A. andrachne, with which it hybridises, than to the western North American madrones sharing its genus. Italy treats it as its national tree because green leaves, white flowers and red berries echo the flag.
Growers find it tough but stingy. Once established it tolerates drought, frost, shade and salt, and unlike most heathers it copes with limy soil. Fruit yields are low and unpredictable, around 46 kg per hectare in one two-year study, and seeds rarely germinate above 20 percent. The berries are about 40 percent sugar but bruise so easily they seldom travel fresh; instead they become jams and spirits such as Portuguese medronho and Albanian raki kocimarje. Bees make a bitter honey from the flowers that is still prized.
Its nectar holds a compound called unedone that fights Crithidia bombi, a common bumblebee parasite. Bees deactivate it on swallowing, and gut microbes reactivate it in the hindgut, where the parasite does most damage. Able to resprout after fire, it is also favoured for Mediterranean reforestation and for breaking up fire-prone pine and eucalyptus plantations.
Source: Arbutus unedo
