Cormus domestica

Cormus domestica, commonly known as service tree or sorb tree, is a species of tree in the rose family (Rosaceae). Its continuous range includes much of Europe as well as northern Anatolia, but isolated populations have been found in the Atlas Mountains of Northwest Africa, and east into the Caucasus and northwestern Iran. It may be called the true service tree, to distinguish it from the wild service tree (Aria torminalis, syn. Sorbus torminalis). It is commonly classified as the only species in the monotypic genus Cormus, although the synonym Sorbus domestica continues to be used.

Taxonomy and evolution

Taxonomic history The service tree was formally described by Carl Linnaeus as Sorbus domestica in his Species Plantarum (1753). In the aftermath, it was included in several other genera, including Cormus, Crataegus, Malus, Mespilus and Pyrus. Since the early 20th century, it has been mainly included in a broadly circumscribed genus Sorbus or, alternatively, within the usually monotypic genus Cormus. Starting in the late 2010s, its classification in Cormus tended to be preferred, but Sorbus domestica continues to be used (as of July 2026).

Evolution Within Maleae, the service tree is usually classified within a clade that includes genera such as Pyrus, Sorbus, Aria, and Micromeles. However, the exact relationships within that clade are poorly resolved, owing to a particularly complicated evolutionary history, likely involving rapid diversification and extensive hybridisation. While there are no studies focused on the service tree's origin, its divergence time has been estimated by three studies, with differing results, placing it in either the late Eocene ( ago), the early Oligocene ( ago), or the late Miocene ().

Fossil remains across Europe have been attributed to the service tree or its close extinct relatives. Fossils dating to the late Miocene () of Senigallia, Italy, that were initially described as Sorbus synoica, have been attributed to the species. Additionally, fossils from the late Pliocene () of Willershausen, Germany, and early Pleistocene (between ) fossils from Bernasso (France), Crespiá (Spain), and Oriolo (Italy) have been attributed to the species, and similar leaf fossils have also been reported from the late Pleistocene () from the vicinity of Rome and the late Miocene of Chiuzbaia, Romania. Rowan (Sorbus aucuparia) leaves can be very similar to service tree leaves, however, particularly when growing on dry sites.

Description The service tree is deciduous and grows (rarely ) tall with a trunk up to diameter, though it can also be a shrub tall on exposed sites. The bark is brown, smooth on young trees, becoming scaly and rough on older trees. The winter buds are green, with a sticky, resinous coating. The leaves are long, pinnate with 13–21 leaflets long and broad. The leaves have a bluntly acute apex, and a serrated margin on the outer half or two thirds of the leaflet. The margin of the leaflets is et with slender teeth, except towards the base, which is entire, glabrous above and more or less downy beneath, becoming glabrous or nearly so by autumn.

The flowers are diameter, with five white petals and 20 creamy-white stamens; they are produced in corymbs diameter in late spring, and are hermaphrodite and insect pollinated. The fruit is a human-edible pome called the "serviceberry" that is long, greenish-brown, and often tinged red on the side exposed to sunlight; it can be either apple-shaped (f. pomifera (Hayne) Rehder) or pear-shaped (f. pyrifera (Hayne) Rehder).Rushforth, K. (1999). Trees of Britain and Europe. Collins .Mitchell, A. f. (1974). A Field Guide to the Trees of Britain and Northern Europe, p 280. Collins

Ecology

Cormus domestica is generally rare, listed as an endangered species in Switzerland and Austria, and uncommon in Spain. In the UK, one very old tree that existed in the Wyre Forest before being destroyed by fire in 1862 used to be considered native, but it is now generally considered to be more likely of cultivated origin, probably from a mediaeval monastery orchard planting. More recently, a small population of genuinely wild specimens was found growing as stunted shrubs on cliffs in south Wales (Glamorgan) and nearby southwest England (Gloucestershire). It is a very rare species in Britain, occurring at only a handful of sites. Its largest English population is within the Horseshoe Bend Site of Special Scientific Interest at Shirehampton, near Bristol.

A further population has been discovered growing wild in Cornwall on a cliff in the upper Camel Estuary.

It is a long-lived tree, with ages of 300–400 years estimated for some in Britain.

One of the largest and probably oldest known specimens in Europe is on an educational trail near the town of Strážnice in the province of Moravia, Czech Republic. Its trunk measures in circumference, with a crown high and across. It is estimated to be around 450 years old.The Service Tree. The Tree for a New Europe www.treeforeurope.com, accessed 4 May 2021

Cultivation and uses

The fruit is a component of a cider-like drink which is still made in parts of Europe. Picked straight off the tree, it is highly astringent and gritty; however, when left to blet (overripen) it sweetens and becomes pleasant to eat. In the Moravian Slovakia region of the Czech Republic, there is a community-run museum with an educational trail and a festival for this tree, with products like jam, juice and brandy made from its fruit.Hrdousek V. et al: "Oskeruše - strom pro novou Evropu" (tr. "Oskeruše - a tree for a new Europe"). Brazda, Hodonin, 2014, 240 pages; 550 pictures

In ancient Greece, the fruit was cut in half and pickled, which in Plato's Symposium (190d7-8) has Aristophanes use as a metaphor for the cutting in half of the original spherical humans by Zeus.

Service tree wood was often used for manufacturing wooden planes of all types used for working wood, because servicetree wood is fairly dense and holds a profile well.

Etymology and other names The English name comes from Middle English serves, plural of serve, from Old English syrfe, borrowed from the Latin name sorbus; it is unrelated to the verb serve.Oxford English Dictionary Other English names include sorb, sorb tree, and whitty pear—"whitty" because the leaves are similar to rowan (i.e. pinnate), and "pear" due to the shape of the fruit. The name sorb, likewise, is from the Latin sorbus; because of its fruit and has nothing to do with the Slavic ethnic groups known as the Sorbs and Serbs.

References

Sources cited

Cormus domestica

Bron en licentie