Rhus glabra

Rhus glabra, the smooth sumac, (also known as white sumac, upland sumac, or scarlet sumac) is a North American species of sumac in the family Anacardiaceae.

Description

A bushy shrub. It grows 1.8-3.7 m tall. It spreads 2.4 m wide. The leaves are alternate and compound. The leaves are 30 cm long and there are 11-31 leaflets. The leaflets are smooth. They are 5-10 cm long. They have whitish hairs. The leaflets are sword shaped and have teeth along the edge. The leaves turn red and yellow in autumn. The flowers are 3 mm wide and have 5 white petals. They are crowded in large clusters 20 cm long. The fruit are scarlet and hairy. They occur in clusters. It will form hybrids with staghorn sumac.

Edible Uses

The fruit can be eaten raw or cooked and has an acid flavour; it has been used as a lemon juice substitute. Although small with little flesh, the fruit grows in large panicles and is easily harvested. Soaked for 10–30 minutes in hot or cold water, it makes a refreshing lemonade-like drink. The mixture should not be boiled, as this releases tannic acids and makes the drink astringent. The peeled root can be eaten raw, though this should be treated with some caution due to possible toxicity. Young shoots, peeled, may also be eaten raw, again with some caution. The bark has been eaten as a delicacy by children, though this too should be treated with caution due to possible toxicity.

Traditional Uses

The berries are eaten. They can be dried. They are used to make a sour drink. The fruit are bruised in water, then the liquid strained through a cloth and sugar added. The raw young shoots are eaten as a salad. The peeled roots are eaten raw.

Medicinal Uses

Smooth sumach was used medicinally by various Native North American peoples to treat a wide range of complaints, and is occasionally used in modern herbalism for its astringent and antiseptic qualities. It is best used under the supervision of a qualified practitioner, as it can possibly cause skin irritations. A tea from the bark or root bark is alterative, antiseptic, astringent, galactogogue, haemostatic, rubefacient, and tonic. It treats diarrhoea, fevers, general debility, sore mouths, rectal bleeding, and uterine prolapse, and is used as a gargle for sore throats and applied externally for excessive vaginal discharge, burns, and skin eruptions. Powdered bark applied as a poultice to old ulcers acts as a good antiseptic. A tea from the roots is appetizer, astringent, diuretic, and emetic, used for colds, sore throats, painful or retained urination, and dysentery. Roots are harvested in autumn and dried for later use. An infusion of green or dried branches treats TB. A decoction of branches with seed heads treats itchy scalps and is used as a bathing water for frost-bitten limbs. The milky latex has been used as a salve on sores. Leaf tea treats asthma, diarrhoea, and stomatitis; a leaf poultice treats skin rashes; leaves have been chewed for sore gums and rubbed on lips for soreness. The berries are diuretic, emetic, emmenagogue, purgative, and refrigerant, used for late-onset diabetes, strangury, bowel complaints, febrile diseases, and dysmenorrhoea, and have been chewed as a remedy for bed-wetting. The blossoms have been chewed for sore mouths; a decoction used as a mouthwash for teething children; and an infusion used as an eyewash for sore eyes.

Known Hazards

There are some suggestions that the sap of this species can cause a skin rash in susceptible people, but this has not been substantiated. See also notes in 'Cultivation Details'.

Distribution

It is a temperate plant. It is frost hardy. It grows especially on sandy soils. It grows up to about 2,000 m altitude in SE regions of the USA. It suits hardiness zones 2-9. Arboretum Tasmania.

Where It Grows

Australia, Britain, Canada, Europe, Mexico, North America, Tasmania, USA,

Cultivation

Succeeds in a well-drained fertile soil in full sun. Tolerates poor sandy soils. A very hardy plant, when fully dormant it can tolerate temperatures down to at least -25°c. However, the young growth in spring can be damaged by late frosts. A fast-growing but short-lived plant in the wild. Single-stem plants are short-lived in cultivation, but if the plants are coppiced regularly and allowed to form thickets, then they will live longer and also be more ornamental with larger leaves. Any coppicing is best carried out in early spring. It is a very ornamental plant, there are some named varieties. Closely allied to R. typhina, it hybridizes with that species where their ranges overlap. Plants have brittle branches and these can be broken off in strong winds. Plants are also susceptible to coral spot fungus. Plants in this genus are notably resistant to honey fungus. A good bee plant. Many of the species in this genus are highly toxic and can also cause severe irritation to the skin of some people, whilst other species such as this one are not poisonous. It is relatively simple to distinguish which is which, the poisonous species have axillary panicles and smooth fruits whilst non-poisonous species have compound terminal panicles and fruits covered with acid crimson hairs. The toxic species are sometimes separated into their own genus, Toxicodendron, by some botanists. Dioecious. Male and female plants must be grown if seed is required. The berries are typically harvested in late summer to early autumn, around August to September (Northern Hemisphere, when they are fully ripe. Sumac generally flowers in early to mid-summer, usually from June to July (Northern Hemisphere). Sumac species typically grow at a moderate pace, reaching maturity within a few years, and can establish rapidly in suitable conditions.

Propagation

Seed is best sown in a cold frame as soon as it is ripe. Pre-soak for 24 hours in hot water (starting at 80–90°C and allowed to cool) to leach out germination inhibitors; this soak water has a delicious lemon flavour and can be drunk. Stored seed also requires hot water treatment and can be sown in early spring in a cold frame. Prick seedlings into individual pots when large enough to handle and grow on under glass for their first winter. Plant out in late spring or early summer after the last expected frosts. Half-ripe cuttings of 10cm with a heel can be taken in July/August in a frame. Root cuttings 4cm long taken in December should be potted vertically in a greenhouse — good success rate. Suckers can be taken in late autumn to winter.

Other Uses

Sumac is useful for erosion control and as a hedge or border plant, with dense growth providing wildlife cover. The leaves contain about 10–25% tannin (up to 31.2% in some plants) and can be collected in autumn as a brown dye or mordant. Twigs and roots are also rich in tannin. The fruit yields black and red dyes. Leaves, bark, and roots yield a black dye. Roots harvested in spring give an orange or yellow dye. Stem pulp gives a light yellow dye. Inner bark mixed with bloodroot (Sanguinaria canadensis) and wild plum inner bark (Prunus sp.) yields a yellow dye. An oil extracted from the seeds attains a tallow-like consistency and is used to make candles that burn brilliantly but emit pungent smoke. The plant's extensive root system and wind tolerance make it suitable for soil stabilization and use as a shelter screen. It establishes quickly in open sunny locations and can serve as a pioneer species for woodland establishment. Wood is soft, light, and brittle. Sumac flowers attract bees, wasps, and butterflies with nectar and pollen. Red fruit clusters feed birds and small mammals, and the shrubby form provides shelter and nesting sites. Fallen leaf litter shelters invertebrates and overwintering insects.

Other Information

The fruit are eaten especially by children.

Notes

There are about 200 Rhus species.

Synonyms

Also Known As

Smooth Sumac (R. glabra)

References (32)

• Beckstrom-Sternberg, Stephen M., and James A. Duke. "The Foodplant Database." http://probe.nalusda.gov:8300/cgi-bin/browse/foodplantdb.(ACEDB version 4.0 - data version July 1994)
• Bioversity New World Fruits Database
• Bodkin, F., 1991, Encyclopedia Botanica. Cornstalk publishing, p 881
• Bremness, L., 1994, Herbs. Collins Eyewitness Handbooks. Harper Collins. p 119
• Brickell, C. (Ed.), 1999, The Royal Horticultural Society A-Z Encyclopedia of Garden Plants. Convent Garden Books. p 883

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