Prunus emarginata has been included within Prunus pensylvanica by some botanists. Given that much of the problem of separating the two species arises from intermediate plants that are found in British Columbia and western Montana (where the ranges of the two species meet), this makes some sense from a Canadian perspective. However, when viewed from a continental perspective, Prunus emarginata normally does not look much like Prunus pensylvanica and so the two are treated here as distinct[].
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: Pin Cherry

General Information

Prunus pensylvanica is an unarmed, deciduous shrub or a tree with a narrow, round-topped crown; it usually grows from 2 - 16 metres tall, though specimens up to 30 metres have been found in the Appalachian Mountains. The bole is usually 10 - 50cm in diameter. The plant often suckers and can form thickets[, , ].
The tree is harvested from the wild for local use as a food, medicine and source of materials. It can be used as a pioneer species for restoring native woodland.
Prunus pensylvanica is a widespread species with a stable global population. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

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

Northern and Eastern N. America - British Columbia and Northwest Territories to Newfoundland, south to Wyoming, Tennessee and Georgia.

Habitat

Forming thickets along streams and lakeshores, in clearings, roadsides, burned-over areas, disturbed sites, rocky hillsides, cliffs, open forests; at elevations up to 2,800 metres[]. Prefers wet woodlands, old tamarack bogs and interdunal swamps[].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	12.00 m
Growth Rate	Fast
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

Prunus pensylvanica has a wide climatic adaptability. It has been shown to tolerate temperatures down to around -45°c in Colorado, for example[]. The mean annual rainfall can vary from 410mm in the west to 2,030mm in the north. The growing season can vary from 100 - 210 days[]
Requires a sunny position[] and soon dying out if in the shade of other trees[]. Tolerant of a wide range of soils from sandy and gravelly to loams, succeeding in fairly dry soils and in nutrient-poor soils[]. Thrives in a well-drained moisture-retentive loamy soil, growing well on limestone[, ]. Prefers some lime in the soil but is likely to become chlorotic if too much lime is present[]. Prefers a pH in the range 5 - 6, though it is tolerant of more acid conditions[].
A fast growing but short-lived tree[, ]. It can commence flowering when only 2 years old, but usually dies after 20 - 40 years[].
Seeds can remain viable in the soil for more han 50 years[].
The plant can resprout from the base if cut back to the ground, though it appears that, following a fire, regeneration comes mainly from seeds that are stimulated to germinate by the altered conditions[].
Closely related to Prunus emarginata, and hybridizing with it where their ranges overlap[].
The fruit is very attractive to birds[].
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[].

Edible Uses

Fruit - raw or cooked[, , , , ]. A thin sour flesh[, ]. Usually too sour to be eaten raw, it is used mainly for making pies, jellies etc[, ]. The red, globose fruit is about 6 - 10mm in diameter and contains one large seed[, , ].

A gum that exudes from the trunk can be used as a chewing gum[].

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

Medicinal

An infusion of the bark has been used in the treatment of fevers, bronchitis, coughs and colds, infections and blood poisoning[].

A decoction of the inner bark has been used in the treatment of laryngitis[]. A poultice of the boiled, shredded inner bark has been applied to a bleeding umbilical cord[]. An infusion of the inner bark has been used as an eye wash for sore eyes[].

The astringent root bark has been used as a wash on old sores and ulcers[]. A decoction of the root has been used as a treatment for stomach pains[].

The fruit is often used domestically in the preparation of cough mixtures[].

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:

The tree has a vigorous root system and is sometimes planted to stabilise soils and contain erosion[]. It grows naturally on unreclaimed coal mine spoils[].
This species plays a vital role in the regeneration of forests in its native habitats, acting as a nurse tree until it is shaded out by other trees[, ]. It often springs up in burnt-over areas from seed spread by birds and mammals[]. It establishes quickly, providing shelter for other woodland trees and then dying out[].
A good bee plant, providing nectar[, ].

Other Uses

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

The outer bark is used to ornament baskets. It is watertight and resists decay[].

The plant has been used as a rootstock for the sour cherry (Prunus cerasus)[].

The wood is light in weight, moderately soft, weak and close grained[]. It weighs 31lb per cubic foot[]. It is used for fuel and can be harvested as a source of biomass for fibre (presumably for paper pulp 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 sunny position in a cold frame as early in the year as possible[, ]. The stored seed is best given 2 months warm followed by 3 months cold stratification[]. 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[, ]. A very low percentage[].
Softwood cuttings from strongly growing plants in spring to early summer in a frame[].
Layering in spring.