There has been considerable uncertainty amongst botanists as to the best way of treating the genus Rhus, with some viewing it in a strict sense as comprising of around 35 species and electing to separate the other species into several distinct genera; whilst others prefer to view the genus in a looser sense being comprised of perhaps 250 species grouped into several subgenera. The genus is treated here in its strict sense, with many other species that have at times been included here being moved to the genera Cotinus, Searsia and Toxicodendron.
Rhus copallinum is treated here as comprising several distinct, geographical forms. Some botanists, howver, divide the species into several distinct species.

Common Name: Dwarf Sumach

General Information

Rhus copallinum is a deciduous shrub usually growing up to 3 metres tall, though the plant can become more tree-like in the south of its range, sometimes reaching 9 metres with a bole up to 25cm in diameter and a broad, open-topped crown. The plant produces suckers at the roots and can form thickts that are capable of spreading outwards for a metre or more each year[, ].
The plant is harvested from the wild for local use as a food, medicine and source of materials. It has also been used as a commercial source of tannins[]. It can be grown in reforestation and soil stabilization projects and is often grown as an ornamental, valued especially for its autumn colour[].

Known Hazards

The genus Rhus is being treated in its strict sense here, so it excludes the many species with highly toxic and irritant sap (these are included in Toxicodendron). Although the two genera are very similar, it is relatively simple to distinguish which is which, the poisonous species (Toxicodendron) have axillary panicles and smooth fruits whilst non-poisonous species (Rhus) have compound terminal panicles and fruits covered with acid crimson hairs[, ].
Whilst the genus Rhus in this treatment is generally seen as having a non-toxic sap there are some suggestions that the sap of some species in the genus (including this one) can cause a skin rash in susceptible people.

Botanical References

, ,

Range

Eastern N. America - Ontario to Maine, south to Texas ans Florida.

Habitat

Generally found in dry soils on hillsides, along the margins of woodlands and roads, and in abandoned fields[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	2.00 m
Growth Rate	Fast
Pollinators	Bees
Self-fertile	No
Cultivation Status	Ornamental, Wild

Cultivation Details

Rhus copallinum is a very cold-hardy species, when fully dormant it can tolerate temperatures down to about -25°c[]. However, the young growth in spring is much more tender and can be damaged by late frosts. Plants grow best in areas with hot summers.
Succeeds in a well-drained fertile soil in full sun[, ]. Tolerates poor soils[, ]. Established plants are drought resistant[].
A very ornamental plant[]. It is quite fast-growing but short-lived in the wild[].
In the north of its range plants are dwarf, around 1.2 metres tall, but in the south they can be up to 7 metres tall[]. Rhus copallinum is usually a shrub and is found in moist soils in sun or shade[]. The form Rhus copallinum lanceolata. Gray. is more tree-like and is found in drier soils[].
The plant transplants easily[].
Plants have brittle branches and these can be broken off in strong winds[]. They are also shallow-rooted and can be blown over when growing in esxposed conditions[]. Plants are also susceptible to coral spot fungus[].
Plants in this genus are notably resistant to honey fungus[].
A usually dioecious species, though occasional plants are found bearing both male and female flowers. In general both male and female forms must be grown if fruit and seed are required[].

Edible Uses

Fruit - raw or cooked[, , ]. An agreeable acid flavour[]. The fruit is only 3 - 5mm long with very little flesh, but it is borne on dense panicles and is thus easily harvested[]. When soaked for 10 - 30 minutes in hot or cold water it makes a very refreshing lemonade-like drink (without any fizz of course)[, , , , ]. The mixture should not be boiled since this will release tannic acids and make the drink astringent.

Medicinal

A decoction of the root has been used in the treatment of dysentery[]. An infusion of the roots has been used in the treatment of VD[]. A poultice of the root has been applied to sores and skin eruptions[].

A tea made from the bark has been drunk to stimulate milk flow in nursing mothers. A decoction of the bark has been used as a wash for blisters and sunburn blisters[, ].

An infusion of the leaves has been used to cleanse and purify skin eruptions[].

The berries were chewed in the treatment of bed-wetting and mouth sores[, ].

Some caution is advised in the use of the leaves and stems of this plant, see the notes above on toxicity.

Agroforestry Uses:

The plant is a natural pioneer species, being often found in very disturbed sites. It can be grown in the early stages of restoring native woodlands, doing very well on slopes, where its extensive root system makes it useful for stabilizing soils[].
The plant is sometimes grown as a hedge[].

Other Uses

The leaves are rich in tannin[, , , ], so is the bark[] and the fruit[]. The leaves can be collected as they fall in the autumn and used as a brown dye or as a mordant[, ]. The leaves contain 10 - 25% tannin[]. Up to 35.8% has been obtained from some plants[].

An oil is extracted from the seeds[]. It attains a tallow-like consistency on standing and is used to make candles. These burn brilliantly, though they emit a pungent smoke[].

A black dye is obtained from the fruit[, ].

A resin, 'copal resin', is obtained from the sap of this plant. When dissolved in any volatile liquid, such as oil of turpentine, it makes a beautiful varnish[]. (Is this a mistaken entry? Perhaps it belongs with one of the toxic species[]).

The heartwood is a light, greenish brown, the thin band of sapwood is whitish. The wood is light in weight, soft, not strong, coarse grained[, ]. It weighs 32lb per cubic foot[]. It is sometimes used for small posts[].

Propagation

Seed - best sown in a cold frame as soon as it is ripe. Pre-soak the seed for 24 hours in hot water (starting at a temperature of 80 - 90c and allowing it to cool) prior to sowing in order to leach out any germination inhibitors[]. This soak water can be drunk and has a delicious lemon-flavour. The stored seed also needs hot water treatment and can be sown in early spring in a cold frame[]. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts.
Cuttings of half-ripe wood, 10cm with a heel, mid summer in a frame[].
Root cuttings 4cm long taken in December and potted up vertically in a greenhouse. Good percentage[, ].
Suckers in late autumn to winter[].