Prunus mexicana

S. Watson

Mexican Plum

Rosaceae Edible: Fruit, Seeds Potential hazards — see below 9,958 iNaturalist observations

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Summary

Prunus mexicana, commonly known as the Mexican plum, inch plum, and bigtree plum, is a North American species of plum tree that can be found in the central United States and Northern Mexico.

Description

A small tree. It has a single trunk. The crown is open. It grows 6 m tall. The trunk is 15 cm wide. The leaves are 5-11 cm long by 3-5 cm wide. They are narrowly oval with a long pointed tip. There are fine double teeth along the edge. The leaves are yellow-green above and paler underneath. There are prominent veins underneath. The leaf stalks have 1-3 gland dots near the tip. The flowers are 19 mm long with 5 rounded white petals. There are 2-4 flowers in clusters on slender stalks. The fruit is a plum. It is 1.2-2.5 cm wide. The skin is purplish-red. It has a white bloom. The flesh is sweet. The stone is large.

Edible Uses

The fruit can be eaten raw or cooked; it is about 30mm in diameter with thick, juicy flesh, though palatability varies and it holds little commercial value. It contains one large seed. The seed is also edible raw or cooked, but should not be eaten if it tastes too bitter.

Traditional Uses

The plums are eaten fresh or dried. They are also used for preserves.

This uses section is brief — help expand it

Medicinal Uses

No specific medicinal use has been recorded for this species, but all members of the genus contain amygdalin and prunasin, which break down in water to form hydrocyanic acid (prussic acid). In small amounts this highly poisonous compound stimulates respiration, improves digestion, and produces a sense of well-being.

Known Hazards

Although no specific mention has been seen for this species, it belongs to a genus where most, if not all members of the genus produce hydrogen cyanide, a poison that gives almonds their characteristic flavour. This toxin is found mainly in the leaves and seed and is readily detected by its bitter taste. It is usually present in too small a quantity to do any harm but any very bitter seed or fruit should not be eaten. In small quantities, hydrogen cyanide has been shown to stimulate respiration and improve digestion, it is also claimed to be of benefit in the treatment of cancer. In excess, however, it can cause respiratory failure and even death.

Distribution

It is a Mediterranean climate plant. It grows up to 450 m altitude in SE region of the USA. It grows on the edge of the forest and the prairie.

Where It Grows

Canada, Central America, Mexico, North America, USA,

Cultivation

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. Established plants are rather drought resistant. This species is closely related to P. americana. 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.

Propagation

Seed requires 2–3 months of cold stratification and is best sown in a cold frame as soon as it is ripe. Stored seed should be sown in a cold frame as early in the year as possible, with protection from mice. Germination can be slow, sometimes taking 18 months. Prick seedlings into individual pots when large enough to handle, overwinter in a greenhouse or cold frame, then plant out in late spring or early summer the following year. Half-ripe cuttings with a heel can be taken in July/August in a frame; softwood cuttings from vigorous plants in spring to early summer in a frame. Layering in spring is also an option.

Other Uses

The tree has been used as a rootstock for cultivated plums in North America. A green dye can be obtained from the leaves, and a dark grey to green dye from the fruit. The wood is hard and heavy but is seldom used commercially due to the tree's small size.

Notes

There are about 200 Prunus species.

Also Known As

Bigtree Plum, Ciruela de monte, Inch plum

References (7)

Grandtner, M. M., 2008, World Dictionary of Trees. Wood and Forest Science Department. Laval University, Quebec, Qc Canada. (Internet database http://www.wdt.qc.ca)
Jordan, J., et al, 2006, Vascular Plants Utilized by the Plains Apache in Southwestern Oklahoma, Publications of the Oklahoma Biological Survey. 2nd Series. Volume 7: 24-33, 2006
Kermath, B. M., et al, 2014, Food Plants in the Americas: A survey of the domesticated, cultivated and wild plants used for Human food in North, Central and South America and the Caribbean. On line draft. p 713
Little, E.L., 1980, National Audubon Society Field Guide to North American Trees. Alfred A. Knopf. p 501
Plants for a Future, The Field, Penpol, Lostwithiel, Cornwall, PL22 0NG, UK. http://www.scs.leeds.ac.uk/pfaf/

Show all 7 references