Description:
Rowans are mostly small deciduous trees 10-20 m tall, though a few are shrubs. The leaves are arranged alternately, and are pinnate, with (7-)11-35 leaflets; a terminal leaflet is always present.
The flowers are borne in dense corymbs. Each flower is creamy white, and 5-10 mm across with five petals.
The fruit is a small pome 4-8 mm diameter, bright orange or red in most species, but pink, yellow or white in some Asian species. The fruit is soft and juicy, which makes them a very good food for birds, particularly waxwings and thrushes, which then distribute the rowan seeds in their droppings.
Due to their small size the fruit is often referred to as berries, but a berry is a simple fruit produced from a single ovary, whereas a pome is an accessory fruit.
The name rowan was originally applied to the species Sorbus aucuparia, and is also used for other species in Sorbus subgenus Sorbus. Rowans are unrelated to the true ash trees which belong to the genus Fraxinus, family Oleaceae, though the leaves of both are superficially similar.
In the Canadian provinces of Newfoundland and Labrador and Nova Scotia this species is commonly referred to as a “Dogberry” tree.
Rowans are mostly small deciduous trees 10-20 m tall, though a few are shrubs. The leaves are arranged alternately, and are pinnate, with (7-)11-35 leaflets - a terminal leaflet is always present.
The flowers are borne in dense corymbs. Each flower is creamy white, and 5-10 mm across with five petals. The fruit is a small pome 4-8 mm diameter, bright orange or red in most species, but pink, yellow or white in some Asian species. The fruit are soft and juicy, which makes them a very good food for birds, particularly waxwings and thrushes, which then distribute the rowan seeds in their droppings. Due to their small size the fruits are often referred to as berries, but a berry is a simple fruit produced from a single ovary, whereas a pome is an accessory fruit.
Rowan is used as a food plant by the larvae of some Lepidoptera species; see Lepidoptera that feed on Sorbus.
The best-known species is the European Rowan Sorbus aucuparia, a small tree typically 4-12 m tall growing in a variety of habitats throughout northern Europe and in mountains in southern Europe and southwest Asia. Its berries are a favourite food for many birds and are a traditional wild-collected food in Britain and Scandinavia. It is one of the hardiest European trees, occurring to 71° north in Vardø in Arctic Norway, and has also become widely naturalised in northern North America.
The greatest diversity of form as well as the largest number of Rowan species is in Asia, with very distinctive species such as Sargent’s Rowan Sorbus sargentiana with large leaves 20-35 cm long and 15-20 cm broad and very large corymbs with 200-500 flowers, and at the other extreme, Small-leaf Rowan Sorbus microphylla with leaves 8-12 cm long and 2.5-3 cm broad. While most are trees, the Dwarf Rowan Sorbus reducta is a low shrub to 50 cm tall. Several of the Asian species are widely cultivated as ornamental trees.
Species:
North American native species in this subgenus include the American mountain-ash Sorbus americana and Showy mountain-ash Sorbus decora in the east and Sitka mountain-ash Sorbus sitchensis in the west.
Several of the Chinese species, such as White-fruited rowan (Sorbus glabrescens) are popular for their unusual fruit colour, and Sargent’s rowan (Sorbus sargentiana) for its exceptionally large clusters of fruit. Numerous cultivars have also been selected for garden use, several of them, such as the yellow-fruited Sorbus ‘Joseph Rock’, of hybrid origin. They are very attractive to fruit-eating birds, which is reflected in the old name “bird catcher”.
The wood is dense and used for carving and turning and for tool handles and walking sticks.[5] Rowan berries are a traditional source of tannins for mordanting vegetable dyes.
Uses:
The fruit of European Rowan (Sorbus aucuparia) can be made into a slightly bitter jelly which in Britain is traditionally eaten as an accompaniment to game, and into jams and other preserves, on their own, or with other fruits.
The fruit can also be a substitute for coffee beans, and have many uses in alcoholic beverages - to flavour liqueurs and cordials, to produce country wine, and to flavour ale. In Austria a clear rowan berry schnapps is distilled which is called by its German name Vogelbeer.
Rowan cultivars with superior fruit for human food use are available but not common. Mostly the fruits are gathered from wild trees growing on public lands.
Rowan fruit contains sorbic acid, an acid that takes its name from the Latin name of the genus Sorbus. Raw berries also contain parasorbic acid which causes indigestion and can lead to kidney damage, but heat treatment (cooking, heat-drying etc.) and, to a lesser extent, freezing, neutralises it by changing it to the benign sorbic acid. Luckily, they are also usually too astringent to be palatable when raw. Collecting them after first frost (or putting in the freezer) cuts down on the bitter taste as well.
Interesting Facts/Myths:
In Sweden, it was also thought that if the rowan trees grew pale and lost color, the fall and winter would bring much illness.
In Newfoundland, popular folklore maintains that a heavy crop of berries means a hard or difficult winter. Similarly, in Finland and Sweden, the number of berries on the trees was used as a predictor of the snow cover during winter. This is now considered mere superstition (however one can hear old men talk of it), as fruit production for a given summer is related to weather conditions the previous summer, with warm, dry summers increasing the amount of stored sugars available for subsequent flower and fruit production. It has no predictive relationship to the weather of the next winter. Contrary to the above, in Maalahti, Finland the opposite was thought. If the rowan flowers were plentiful then the rye harvest would also be plentiful. Similarly, if the rowan flowered twice in a year there would be many potatoes and many weddings that autumn. And in Sipoo people are noted as having said that winter had begun when the waxwings (Bombycilla garrulus) had eaten the last of the rowan berries.
