Prunus gracilis

Prunus gracilis, called the Oklahoma plum, sour plum, and sand plum, is a species of Prunus native to the south-central United States.

Description

A shrub. It grows 1.5 m tall. The leaves are 2-5 cm long by 1-2.5 cm wide. The flowers are in clusters of 2-4. The fruit are yellow to red. They are 1.5-1.8 cm long.

Edible Uses

The fruit can be eaten raw or cooked, though it is not of particularly good quality. It is usually dried for winter use or cooked. The fruit is about 18mm in diameter and contains one large seed. The seed can also be eaten raw or cooked, but should not be consumed if it is too bitter.

Traditional Uses

The fruit are dried and used to make candy. The fruit can be eaten uncooked or pounded and made into cakes. The fruit are dried and stored for later use.

Medicinal Uses

No specific medicinal use has been recorded for this species, but like all members of the genus it contains amygdalin and prunasin, compounds that break down in water to release hydrocyanic acid (cyanide or prussic acid). In small amounts, this highly poisonous substance is said to stimulate respiration, improve digestion, and produce 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

Temperate.

Where It Grows

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. 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 and protected from mice. Germination can be slow, sometimes taking 18 months. Prick out seedlings into individual pots when large enough to handle, overwinter in a greenhouse or cold frame, and plant out in late spring or early summer the following year. Cuttings of half-ripe wood with a heel can be taken in July or August in a frame. Softwood cuttings from strongly growing plants can be taken in spring to early summer in a frame. Layering can be done in spring.

Other Uses

A green dye can be obtained from the leaves, and a dark grey to green dye from the fruit.

Notes

There are about 200 Prunus species.

Also Known As

Sour plum, Prairie cherry

References (7)

• Boston J. Nat. Hist. 5:243. 1845
• Hedrick, U.P., 1919, (Ed.), Sturtevant's edible plants of the world. p 524
• Illustrated Flora of Central Texas p 934
• 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 712

More from Rosaceae

Rubus serissimus

Chesapeake Blackberry, Everbearing blackberry

Rubus setchuenensis

Rubus setosus

Bristly blackberry, Small bristleberry

Rubus shankii

Shank's blackberry

Rubus sieboldii

Palm-leaf Dewberry

Rubus sikkimensis