There has been a good deal of confusion in botanical works between this species and Prunus avium. But Prunus avium differs from Prunus cerasus in the following respects: it is a tree sometimes of full middle size (Prunus cerasusr is more or less dwarf or shrubby); the leaves are more coarsely toothed and hairy beneath; the fruit is not acid[].
The taxonomic history of Prunus is long and complicated, in part due to the economic value of its fruit crops and also the ease with which some species hybridize. Here, Prunus is circumscribed in its broad sense based on the argument that when viewed on a worldwide scale, the morphologic discontinuities among the segregate genera diminish and they overlap with one another. Included here are species that have at times been placed in the genera Amygdalus, Armeniaca, Cerasus, Laurocerasus, Padus, and Persica.
At the species level, Prunus has been the object of the usual combining and splitting common among taxonomists with different philosophies and opinions. In particular, over-reliance on the indument of various vegetative and floral parts has led to the naming of numerous species and infraspecific taxa. Similarly, too much has been made of fruit colour and palatability in naming taxa of Prunus. It is very likely that, as molecular and genetic data are analyzed and, more importantly, correlated with morphological data, circumscriptions will be redrawn and the number of Prunus species will be reduced[].

Common Name: Sour Cherry

General Information

Prunus cerasus is a deciduous shrub or a tree with a broad rounded crown; it can grow from 3 - 5 metres tall, occasionally to 8 metres. The plant sometimes produces suckers and forms thickets in the wild[, , ].
The sour cherry has been cultivated as a fruit crop since at least 300 BCE. Many named forms have been developed, but the fruit has lost favour in many countries in more recent times. Eastern Europe and western Asia are the main regions in which it is still commonly grown. The plant also has a range of other edible, medicinal and otherl uses.

Known Hazards

The plant (especially the seed and young shoots) contains cyanogenic glycosides, especially amygdalin and prunasin. 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 fruits and flowers of most members of this genus generally have low or very low concentrations of this toxin, though the seeds and young shoots can contain much higher levels.
The levels of toxin can be detected by the level of bitterness:- for example sweet tasting almond seeds are a major food crop and are often eaten in quantity, whilst bitter tasting almond seeds are used as a flavouring (in marzipan for example) but are not usually eaten on their own.
In general, it can be considered safe to eat any fruit or seed from species in this genus that either have a sweet flavour or are slightly bitter. Great caution should be taken, however, if the flavour is moderately to very bitter[].

Botanical References

, ,

Range

Eurasia - the origin of this species is uncertain, it is not known in a truly wild situation, but is often naturalized as an escape from cultivation

Habitat

Hedges in S. England[]. Roadsides, thickets, woodland borders, abandoned fields; at elevations up to 1,000 metres[].

Properties

Edibility Rating
Medicinal Rating
Habit	Deciduous Tree
Height	4.00 m
Pollinators	Bees, Insects
Self-fertile	Yes
Cultivation Status	Cultivated, Ornamental

Cultivation Details

Prunus cerasus is fairly cold-hardy, tolerating temperatures down to about -20°c when fully dormant[].
Thrives in a well-drained moisture-retentive loamy soil[, ]. Prefers some lime in the soil but is likely to become chlorotic if too much lime is present[]. Prefers an acid soil according to another report[]. Succeeds in sun or partial shade though it fruits better in a sunny position[, ]. Plants are succeeding in a fairly exposed maritime position at Rosewarne in N. Cornwall[].
The sour cherry has long been cultivated for its edible fruit, there are many named varieties[, ]. The species is believed to have originated as a natural hybrid between Prunus avium and Prunus fruticosa in the Iranian Plateau or Eastern Europe where the two species come into contact. Prunus fruticosa is believed to have provided its smaller size and its sour tasting fruit. The hybrids then stabilised and interbred to form a new, distinct species from which, over time, many cultivars have been selected.
The various cultivars have been classified into groups by different authors, often placing these groups as different subspecies. There does not, however, appear to be a generally accepted taxonomy for these groups. The following is probably the mose widely accepting grouping:-
Austera Group. These have dark red fruits. The best known variety here is the 'Morello' cherry which is often grown on a garden scale. It is particularly renowned for its late flowering and ability to produce a good crop even when it is grown against a shady wall and recieves little direct sunlight.
Amarelle or Caproniana Group. (syn Prunus acida Ehrh., Prunus caproniana (L.) Gaudin) These have lighter red fruits than the austera group. They include the various forms of the 'Kentish Red' cherry and the Amarelle cherry
Frutescens Group. (syn Cerasus collina Lejeune & Cortois). Smaller growing with a shrubby, suckering habit. Various orchard varieties are cultivated in the Soviet Union, including the old variety known as 'Ostheim'. The dark red fruit is somewhat smaller than average (around 10mm in diameter) with a dark juice and a pleasant acid flavour[, ].
Marasca. (Syn Cerasus marasca Host) The Maraschino cherry is a vigorous tree, found especially around the town of Zadar in Croatia. The fruits are employed in the manufacture of the famous Maraschino liqueur[].
Montmorency. Probably a form of the Amarelle cherry, it is often grown on a commercial basis in Michigan and Wisconsin[]. Most forms have light red fruits, though some trees produce darker fruits. It is very popular for use in cherry pies and for making a juice concentrate with purported health benefits.
Semperflorens. (syn Prunus semperflorens Ehrh.). Now recognized as a cultivar, it is a small, very elegant round-headed tree, with pendent, slender branches and curiously clustered twigs. It produces a small crop of blossom in the middle of spring, and then a second flowering that continues through most of the summer. The fruit is acid, but pleasantly flavoured.
Cultivars of Prunus cerasus with doubled flowers are used as landscape ornamentals[].
Unlike sweet cherry, all widely grown varieties of sour cherry are self-fertile[].
Many cultivars will succeed on a wall that recieves little direct sunlight[].
Most members of this genus are shallow-rooted and will produce suckers if the roots are damaged[]. Plants produce suckers freely[].
Plants in this genus are notably susceptible to honey fungus[].

Edible Uses

Fruit - raw or cooked[, , , , ]. Pleasantly acid, the fruit can be eaten out of hand, used in pies, preserves etc or dried for later use[]. The bright red, globose fruit is about 13 - 18mm in diameter and contains one large seed[, ].

Seed - raw or cooked. Do not eat the seed if it is too bitter - see the notes above on toxicity.

An edible oil is obtained from the seed[, ]. When refined it is used as a salad oil[].

The leaves are used as a tea substitute[, , , ].
The leaves are used as a flavouring when pickling cucumbers[].

A gum obtained from the trunk is used for chewing[, ].

Medicinal

The bark is astringent, bitter and febrifuge[]. An infusion of the bark has been used in the treatment of fevers, coughs and colds[]. The root bark has been used as a wash for old sores and ulcers[].

The seed is nervine[].

Although no specific mention has been seen for this species, all members of the genus contain amygdalin and prunasin, substances which break down in water to form hydrocyanic acid (cyanide or prussic acid). In small amounts this exceedingly poisonous compound stimulates respiration, improves digestion and gives a sense of well-being[].

Agroforestry Uses:

Plants can be grown as a hedge[], succeeding in fairly exposed positions[].
An excellent nectar plant, yielding both nectar and pollen[].

Other Uses

An edible drying oil obtained from the seed is also used in cosmetics[]. Seeds contain an almond -flavoured fatty oil (24 - 35%) which rapidly becomes more bitter; this is used in the manufacture of soap and is suitable for burning. The oil contains a large quantity of amygdalin[].

The stones are used as well: according to American data, 1,000 tons of stones yields 448 tons of kernels which can yield to 96,235.5 kg (95,563 liters) of syrup, 22,736 liters of spirits, 338,130 liters qf gum, 200 tons of powder, 3 tons of essential oil, and 4.134 tons of fatty oil[].

The gum obtained from the stem can be used as an adhesive[, ]. It is used in the manufacture of cloth[] (as a size?).

A green dye can be obtained from the leaves[].
A dark grey to green dye can be obtained from the fruit[].

The plant can be used as a rootstock for cultivated cherries[].
The plant is used in breeding programmes for the sweet cherry.

The bark contains 5 - 7% tannins, including some quercetin[].

The yellowish red wood is compact, rather heavy. It is suitable for use in woodwork and lathework for making pipes, cigarette holders, hoops for barrels etc[].

Propagation

Seed - requires 2 - 3 months cold stratification and is best sown in a cold frame as soon as it is ripe[]. Sow stored seed in a cold frame as early in the year as possible[]. Protect the seed from mice etc. The seed can be rather slow, sometimes taking 18 months to germinate[]. Prick out the seedlings into individual pots when they are large enough to handle. Grow them on in a greenhouse or cold frame for their first winter and plant them out in late spring or early summer of the following year.
Cuttings of half-ripe wood with a heel, mid summer in a frame[].
Softwood cuttings from strongly growing plants in spring to early summer in a frame.
Layering in spring.
Division of suckers during the dormant season. They can be planted out direct into their permanent positions.