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[
Cerasus pseudocerasus (Lindl.) Loudon
Cerasus scopulorum (Koehne) T.T.Yu & L.C.Li
Padus pseudocerasus (Lindl.) S.Ya.Sokolov
Prunus ampla Koehne
Prunus involucrata Koehne
Prunus pauciflora Bunge
Prunus saltuum Koehne
Prunus scopulorum Koehne
Common Name: Cambridge Cherry
Prunus pseudocerasus is a deciduous shrub or a tree that can grow 2 - 8 metres tall[
The plant is often cultivated, especially in China, for its edible fruit. It is also used as a rootstock for the cultivated cherries.
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[
E. Asia - China
Not known in a truly wild situation, though it is often found on sunny mountain slopes and the sides of ravines, usually as a result of cultivation; at elevations from 300 - 600 metres in China[
|Other Uses Rating
Prunus pseudocerasus is fairly cold-hardy, tolerating temperatures down to around -15°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[
]. Succeeds in sun or partial shade though it fruits better in a sunny position[
Prunus pseudocerasus has been cultivated as a fruit crop in China for several hundred years - many cultivars have been developed[
This species is well adapted for growing as small trees in pots, growing them in protected environments to ensure an early crop[
Closely related to Prunus involucrata[
Most members of this genus are shallow-rooted and will produce suckers if the roots are damaged[
Plants in this genus are notably susceptible to honey fungus[
Fruit - raw or cooked and used in preserves etc[
]. Cherry-like, it is large and sweet[
]. The red, subglobose fruit is about 9 - 15mm in diameter and contains one large seed[
]. The fruit contains about 1% protein, 0.8% fat, 16.5% carbohydrate, 0.6% ash[
The flowers are salted and used as a tea[
Seed - raw or cooked. Do not eat the seed if it is too bitter - see the notes above on toxicity.
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[
A green dye can be obtained from the leaves[
A dark grey to green dye can be obtained from the fruit[
Frequently used as cherry rootstock, it is a parent of special interspecific hybrids such as 'Colt' that are used as dwarfing rootstocks for sweet cherries[
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.