Plant Story--the Strawberry Tree, Arbutus unedo

I was a tourist in Portugal and only caught the end of the guide's tale, "...strawberry tree." 

Strawberry tree?! Strawberries don't grow on trees! 

And, that's true, strawberries don't grow on trees, but there is very definitely a tree whose English name is strawberry tree.

strawberry-tree fruit, Arbutus unendo

It is Arbutus unedo, generally called the strawberry tree in English. It is in the heath family, Ericaceae, related to rhododendrons, blueberries, and cranberries, not at all closely related to strawberries, which are Fragaria species in the rose family, Rosaceae.

The eastern U.S.'s arbutus, trailing arbutus, is in the genus Epigaea not Arbutus, but the western U.S. has several species of Arbutus, which go by the common name madrone, an English version of their Spanish name. The Pacific madrone, Arbutus menziesii, is native from California to British Columbia and easily recognized by the distinctive orange-red bark, which it shares with the strawberry tree.  Worldwide, Arbutus is a genus of about 12 shrubs or small trees which are native around the Mediterranean to the Canary Islands and western Ireland, and in the western United States, southwestern Canada, and western Mexico, a curious distribution featuring mild dry climates. 

The range of the strawberry tree itself is all around the Mediterranean (southern Europe, the western Middle East and north Africa) and western Ireland (Kerry and Sligo). How much of that range is natural is unclear, since the tree has been popular with humans since before the Roman era. In the case of Ireland, it could have been brought by ancient Celts, but might also have been there when they arrived (there are other odd plants in western Ireland). Hardy only to USDA zones 7-10, strawberry tree does not survive very far north, and in the U.S. is confined to the South and the Far West.

The strawberry tree name is obvious--photos above, below. Sure looks like a strawberry! Although, in fact, those are small projections on the fruit, which strawberries lack.

strawberry tree fruits

The fruits are edible but uninteresting. The scientific name, Arbutus unedo, is a compound of two names the Romans called this plant. Arbutus may be from the word arbor or at least the same root, but the word unedo, a second Roman name for the plant, is a contraction of unum edo, "I eat [only] one", which is what the Roman naturalist and philosopher Pliny the Elder (23-79 CE) wrote that people said about the fruit. 

strawberry tree leaves

The leaves have been used in traditional medicine, being astringent and antiseptic. They are, as you can see, shiny and attractive. And evergreen. The trees stay green through the winter, rather than dropping their leaves in the fall. 

The fruits are mostly used for jams, or combined with something with more flavor, or to make alcoholic beverages. Most Mediterranean countries have specialty drinks--brandies, wines--made with strawberry tree fruits. The fruits are rich in antioxidants and sugars.

The little bell-like flowers have a lovely scent. They are very attractive to bees and other flower visitors. The honey has a distinctive bitter aftertaste and is a delicacy. 

Strawberry trees grow to about 15' tall and spread equally broadly. (See very nice pictures of them on the California Polytechnic State University's website link.) This is a fall-blooming tree, which is unusual and makes it a welcome addition to a yard. Of course, it only grows in climates where the winter is mild. The fruit takes a year to mature, so trees frequently have both flowers and fruit, a trait much liked by botanists trying to identify them. 

strawberry tree, Arbutus unedo

The wood is reddish brown, hard, and attractive, but splits easily. As a wood, it is mainly used for its color in inlays. Historically the trees were often cut because the wood burns down into excellent charcoal. 

The coat of arms of the city of Madrid, Spain, is a bear reaching up to eat fruits from a strawberry tree fruits (link), The tree was added to the coat of arms which featured a bear, after the city won a dispute about whether the city or the church would take the forage from the local forest (link) but that doesn't explain why it is a strawberry tree, which the red fruits make clear. But, strawberry tree is madroño in Spanish, similar in sound to Madrid and, perhaps, both from the root, madre. It is a visual pun. 

If you know the American madrones, the strawberry tree is easy to recognize, once you know about it. A very pretty and interesting tree. 

Comments and corrections welcome.

References

Author unknown. 2011. The Strawberry Tree - A Kerry native with a very bitter bite. The Kerryman. link (Accessed 28 Dec., 2020).

Bostock, J. and H. T. Riley, editors. 1855. Pliny the Elder.  written about 70 CE. The Natural History. Book 15, Chapter 28. http://data.perseus.org/citations/urn:cts:latinLit:phi0978.phi001.perseus-eng1:15.28 (Accessed 27 Dec., 2020),

Drori, J. 2018. Around the world in 80 trees. Lawrence King Publishing, London.

Martin, J. 2018. The miracle of the strawberry tree. Wandering Italy Blog. link (Accessed 26 Dec. 2020). Includes recipes.

Missouri Botanical Garden. Arbutus unedo. Missouri Plant Finder. link (Accessed 27 Dec., 2020).

Reader's Digest. 1982. Field guide to trees and shrubs of Britain. Reader's Digest Association, London.

Wikipedia. Arbutus unedo. link. (Accessed 26 Dec. 2020.) A very extensive article!

Kathy Keeler, A Wandering Botanist
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