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.

Common Name: Sugar Bush

General Information

Rhus ovata is an evergreen shrub that can grow up to 3 metres tall[].
The plant is harvested from the wild for local use as a food, medicine and source of materials.

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

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Range

South-western N. America - California, Arizona and northern Mexico (Baja Norte)

Habitat

Dry rocky slopes below 800 metres, usually away from the coast, in California[, ]. Grows in oak woodlands and chaparral[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Shrub
Height	2.00 m
Pollinators	Bees
Self-fertile	No
Cultivation Status	Wild

Cultivation Details

Rhus ovata is not very cold-hardy, tolerating occasional, short-lived temperatures falling to around -5°c when it is dormant[]. It requires hot summers if it is to thrive - in areas with cool summers the wood fails to ripen properly and is then even more susceptible to winter damage. The young growth in spring is also very susceptible to cold and can be damaged by late frosts.
Succeeds in a well-drained fertile soil in full sun[, ]. Succeeds in a hot dry position. Plants are usually found in poor dry soils in the wild[].
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 dioecious species - both male and female forms must be grown if fruit and seed are required.

Edible Uses

Fruit - raw or cooked[]. Slightly acid to sweet tasting[]. 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 fruit can also be sucked for the tart juice that forms on its surface[]. Individual fruits are quite small, around 6 - 8mm in diameter and with very little flesh, but they are produced in dense clusters and are easily harvested[, ].

A sweetish white sap exudes from the fruit and can be used as an acid flavouring or a sugar substitute[, ].

The leaves are boiled to make a tea[].

Medicinal

An infusion of the leaves has been used in the treatment of chest pains, coughs and colds[]. An infusion has also been taken just before giving birth to facilitate an easy delivery[].
Some caution is advised in the use of the leaves and stems of this plant, see the notes above on toxicity.

Agroforestry Uses:

Often planted in poor dry soils in America, where its extensive root system helps to prevent erosion[].

Other Uses

The leaves are rich in tannin. They can be collected as they fall in the autumn and used as a brown dye or as a mordant[].

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[].

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[].