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: Cherry Laurel

General Information

Prunus laurocerasus is a strongly-branching, evergreen shrub or a tree, usually growing 2 - 6 metres tall, occasionally reaching 10 metres. The plant is often around twice as wide as it is high, and also sometimes suckers and can form thickets[, , ].
The plant is harvested from the wild for local use as a food, medicine and source of materials. Very widely grown as an ornamental, where selected cultivars can be used as ground cover or hedging.
A greedy plant, inhibiting the growth of nearby plants[], it should be introduced with care since it often self-sows in woodlands and can prevent the successful regeneration of native trees by shading out the seedlings[].

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

E. Europe to W. Asia. More or less naturalized in Britain[].

Habitat

Woods in Britain[]. Riparian thickets, shaded ravines, understory of urban and second-growth forests; at elevations up to 600 metres[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Shrub
Height	4.00 m
Growth Rate	Medium
Pollinators	Bees, Lepidoptera
Cultivation Status	Ornamental, Wild

Cultivation Details

Prunus laurocerasus is a moderately cold-hardy plant, when dormant being able to tolerate temperatures falling to arounf -15°c for short periods.
Requires a well-drained moisture retentive soil[, ]. Grows well in heavy clay soils. Thrives in a loamy soil, doing well on limestone[]. Prefers some chalk in the soil but it is apt to become chlorotic if too much is present, growing badly on shallow chalk[, ]. Extremely tolerant of shade, it succeeds in the dense shade of trees with almost no direct light and in their drip line[, ], though it fruits better in a more sunny position[].
A very ornamental plant, there are many named varieties[]. The cultivar 'Otto Luyken' is a low growing narrow-leafed form that flowers in spring and autumn.
The tiny flowers are powerfully fragrant[] but have a rather offensive odour[]. This is a matter of opinion, some people find the smell sweet and delightful[].
Although all other parts of the plant are more or less poisonous, the fruit is edible, though often bitter. In some garden forms the fruit is large and sweet[, ].
The cultivar 'Camelliifolia' bears huge quantities of fruit[]. This is the size of a large cherry and, when fully ripe, has a reasonable flavour raw with a jelly-like texture and a slight astringency[].
Suitable for landscaping in temperate climates also with variegated leaves[]
A greedy plant, inhibiting the growth of nearby plants[], it should be introduced with care since it often self-sows in woodlands and can prevent the successful regeneration of native trees by shading out the seedlings[].
Most members of this genus are shallow-rooted and will produce suckers if the roots are damaged[].
The flowers attract butterflies and moths[].
This species is notably resistant to honey fungus[, ]. Subject to bacterial canker which can kill large branches[].
Trim (preferably with secateurs) in spring or late summer[]. Old plants can be cut back hard into the old wood in spring and will soon recover[].

Edible Uses

Fruit - raw or cooked. Sweet and reasonably pleasant when fully ripe[, , ]. Some sources suggest the fruit is poisonous, this probably refers to the unripe fruit[]. We have eaten this fruit (fully ripe and with a sweet flavour) in quite large quantities without the slightest ill effects (this also includes a 2 year old child) and so any toxicity is of a very low order[]. However, any fruit that is bitter should not be eaten in quantity because the bitterness is caused by the presence of the toxic compounds - see the notes above on toxicity. The black-purple, ovoid fruit is about 8 - 17mm in diameter and contains one large seed[, ].

Water distilled from the leaves is used as an almond flavouring[, , , ]. It should only be uses in small quantities, it is poisonous in large amounts[].
Bark and buds contain prussic acid. The leaves contain a derivative of this. They are extracted with water to produce
cherry-laurel water containing 1 part of hydrocyanide per 1,000 parts by weight[].

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

Medicinal

The fresh leaves are antispasmodic, narcotic and sedative[, ]. They are of value in the treatment of coughs, whooping cough, asthma, dyspepsia and indigestion[, ].
Externally, a cold infusion of the leaves is used as a wash for eye infections[].
There are different opinions as to the best time to harvest the leaves, but they should only be used fresh because the active principles are destroyed if the leaves are dried[].

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:

Very tolerant of trimming, this plant makes an excellent hedge especially in shady areas[, , ].
Some forms of this plant, notably 'Cherry Brandy', 'Otto Luyken', 'Zabelina' and 'Schipkaensis' are low-growing and make very good ground cover plants for sun or shade[, ].

Other Uses

Water distilled from the leaves is used in perfumery[]. Bark and buds contain prussic acid. The leaves contain a derivative of this. They are extracted with water to produce cherry-laurel water containing 1 part of hydrocyanide per 1,000 parts by weight[].
Cherry laurel oil contains benzaldehyde and prussic acid[].

The bruised leaves, when rubbed within any container, will remove strong odours such as garlic or cloves so long as any grease has first been fully cleaned off[].

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

The pinkish grey wood is used in turnery and lathe work[].

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[, ].
Cuttings of mature wood, early autumn in a sheltered north facing border outdoors[].
Layering in spring.