Sorbus is treated here in the broad sense, including the subgenera Aria and Torminaria. However, these two subgenera are likely to be recognized at generic rank, based on flower and fruit characters, once molecular studies can consistently resolve their placement within the Pyrinae, overcoming current difficulties with interfertility, reticulate relationships, rapid radiation, and small samples[].
The taxonomy of Sorbus is complicated by apomixis, polyploidy, and hybridization among sections and genera, especially in Eurasia. Sorbus hybridizes with several other genera in the tribe Maleae, including Amelanchier (×Amelasorbus Rehder); Crataegus (×Crataegosorbus Makino); Aronia (×Sorbaronia C. K. Schneider); Cotoneaster (×Sorbocotoneaster Pojarkova); Pyrus (×Sorbopyrus C. K. Schneider), and Malus (×Tormimalus Holub [= Sorbus subg. Torminaria × Malus])[].

Common Name: Service Tree

General Information

Sorbus domestica is a deciduous tree that usually grows from 4 - 15 metres tall, with specimens up to 20 metres recorded[, ].
The tree is harvested from the wild for local use as a food, medicine and source of materials. It is occasionally cultivated as a fruit crop and the fruits are sometimes sold in local markets. The tree is also sometimes grown as an ornamental.

Known Hazards

Although no specific information has been seen, the seed, and other parts of the plant, is likely to contain cyanogenic glycosides. When injested, these compounds break down in the digestive tract to release cyanide. Used in small quantities in both traditional and conventional medicine, this exceedingly poisonous compound has been shown to stimulate respiration, improve digestion, and promote a sense of well-being[]. It is also claimed by some to be of benefit in the treatment of cancer - though this claim has been largely refuted.
In larger concentrations, however, cyanide can cause gasping, weakness, excitement, pupil dilation, spasms, convulsions, coma and respiratory failure leading to death[].
The levels of toxin can be detected by the level of bitterness:- sweet almonds, for example, contain only very low levels of it and are safe to eat in quantity, whilst bitter almonds (which are used as a flavouring in foods such as marzipan) contain much higher levels and should only be eaten in very small quantities. Great caution should be employed if the taste is moderately to very bitter[].

Botanical References

, ,

Range

Central and southern Europe - Britain to Spain east to Ukraine Greece and Bulgaria; W. Europe - Turkey; N. Africa - Morocco, Algeria.

Habitat

Woods and bushy places[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	15.00 m
Growth Rate	Medium
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

Sorbus domestica prefers a warm and mild climate, but is moderately cold-hardy, tolerating temperatures down to around -25°c when dormant and able to withstand late frosts after it has come into growth[]. It requires a minimum annual rainfall of 500mm[].
Succeeds in most reasonably good soils in an open sunny position[]. Tolerates light shade[], though it fruits better in a sunny position[]. Established plants are drought tolerant[].
The service tree is occasionally cultivated for its edible fruit[, , ].
There are 2 distinct forms:-
Sorbus domestica pyriformis. (Hayne.)Rehd. Said to be the more ornamental form[], it has pear shaped fruits which ripen from mid autumn[, ].
Sorbus domestica pomifera. (Hayne.)Rehd. This form has apple shaped fruits, which ripen from early autumn[, ].
A single tree is said to be able to produce 600 - 1,000 kilos of fruit[].
A long-lived tree, believed to live for at least 500 - 600 years[].
Plants are susceptible to fireblight[] and to canker (which is especially prevalent in areas with high rainfall)[]. They grow best in the drier areas of Britain, which in general means the eastern half of the country[].

Edible Uses

Fruit - raw or cooked. It can be used to make preserves[]. The fruit is usually bletted if it is going to be eaten raw[, , , , , ]. This involves storing the fruit in a cool dry place until it is almost but not quite going rotten. At this stage the fruit has a delicious taste, somewhat like a luscious tropical fruit[]. The fruit will often begin its bletting process whilst still on the tree and we have eaten delicious fruits straight from the tree in mid-September[]. The fruit can also be dried and used like prunes. The apple or pear-shaped fruit is up to 30mm across[].

The fruit is used to make a fermented drink known as 'kvass'[].

Medicinal

The fruit is mildly diuretic, laxative, antirheumatic and antipyretic It is used in traditional medicine as a treatment against intestinal problems, dysentery, diabetes and also for memory improvement[].

Other Uses

The bark is a source of tannin[].

The reddish-white wood is fine grained, hard, very heavy, difficult to split. Of fine quality, it is used for furniture making, screws, wine presses, lathework, small carved articles etc[, , , , ].

Propagation

Seed - best sown as soon as it is ripe in a cold frame[, ]. If you have sufficient seed it can be sown in an outdoor seedbed[, ]. Stored seed germinates better if given 2 weeks warm then 14 - 16 weeks cold stratification[], so sow it as early in the year as possible. Prick out the seedlings into individual pots when they are large enough to handle. Seedlings are very slow to put on top-growth for their first year or two[], but they are busy building up a good root system. It is best to keep them in pots in a cold frame for their first winter and then plant them out into their permanent positions in late spring.