Slippery Elm

Ulmus rubra

Physical Characteristics

Ulmus rubra is a deciduous Tree growing to 20 m (65ft) by 15 m (49ft) at a medium rate. See above for USDA hardiness. It is hardy to UK zone 3 and is not frost tender. It is in flower from March to May, and the seeds ripen from May to June. The species is hermaphrodite (has both male and female organs) and is pollinated by Wind. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Distribution

Central and Southern N. America - Maine to Florida, west to Texas and North Dakota.

Habitats

Woodland Garden Canopy;

Edible Uses

Edible Parts: Fruit Inner bark Leaves Edible Uses: Tea Leaves - raw or cooked. Inner bark - raw or cooked. It can be dried, ground into a powder and then used as a thickener in soups or added to cereal flours when making bread etc[2, 14, 46, 55, 171]. It can also be chewed as a thirst quencher[227]. The inner bark has been cooked with fats in order to prevent them becoming rancid[257]. Immature fruit - raw or cooked[177]. The fruit is about 20mm in diameter[200]. A tea-like beverage can be brewed from the inner bark[257].

Medicinal Uses

Demulcent Diuretic Emollient Expectorant Nutritive Urinary Slippery elm bark is a widely used herbal remedy and is considered to be one of the most valuable of remedies in herbal practice[4]. In particular, it is a gentle and effective remedy for irritated states of the mucous membranes of the chest, urinary tubules, stomach and intestines[254]. The inner bark contains large quantities of a sticky slime that can be dried to a powder or made into a liquid[229]. The inner bark is harvested in the spring from the main trunk and from larger branches, it is then dried and powdered for use as required[4]. Ten year old bark is said to be best[4]. Fine grades of the powder are best for internal use, coarse grades are better suited to poultices[238]. The plant is also part of a North American formula called essiac which is a popular treatment for cancer. Its effectiveness has never been reliably proven or disproven since controlled studies have not been carried out. The other herbs included in the formula are Arctium lappa, Rumex acetosella and Rheum palmatum[254]. The inner bark is demulcent, diuretic, emollient, expectorant, nutritive[4, 21, 165, 213]. It has a soothing and healing effect on all parts of the body that it comes into contact with[4] and is used in the treatment of sore throats, indigestion, digestive irritation, stomach ulcers etc[222]. It used to be frequently used as a food that was a nutritive tonic for the old, young and convalescents[222]. It was also applied externally to fresh wounds, burns and scalds[222]. The bark has been used as an antioxidant to prevent fats going rancid[222]. The whole bark, including the outer bark, has been used as a mechanical irritant to abort foetuses[238]. Its use became so widespread that it is now banned in several countries[238].

Known Hazards

Outer bark constituents known to cause abortions - avoid during pregnancy [301].