Acokanthera oppositifolia

Description

An exceptionally attractive, hardy, upright, woody shrub or small tree, depending on habitat, with dark brown, deeply fissured bark when mature, long, slender branches that are a lovely russet-red colour upon emergence, and a dense crown of glossy, dark-green, purple or red-tinged leaves with sharply-pointed tips. In spring, the branches are covered in thick clusters of dainty, heavily scented, whitish-pink, tubular flowers, followed by plum-like, purplish black and red berries. All plants of the genus Acokanthera exude a milky latex which contains toxic cardiac glycosides strong enough to cause death.

SA Tree

Family

Apocynaceae (Dogbane family)
A family of trees, shrubs, woody vines and herbs belonging to the order of Gentianales, with more than 400 genera and 4500 species, found primarily in the tropical and subtropical areas of the world.
Many members possess a milky or watery latex, which is often poisonous, but is also used medicinally or as bird lime.
Leaves are typically simple and opposite, or arranged in whorls of 3 or more, with smooth, entire margins.
Flowers are small and grouped in clusters, rarely solitary, and the fruits are either berries or drupes, usually occurring in pairs but sometimes singly.
Many members are highly decorative, such as the Frangipani and Impala Lily (Adenium multiflorum).

Habitat

The most widespread member of its genus in southern Africa, occurring all along the southern and eastern seaboards, with the exception of very dry areas, as well as the northern parts of Gauteng,
North West, Limpopo and Mpumalanga. Also, in Swaziland, Mozambique and Zimbabwe.
The trees typically occur as part of the understorey vegetation in forests or at forest margins, but can be found in a variety of habitats, from rocky outcrops, coastal and riverine thickets, to open woodlands and grassland.

Bark

Foliage

Evergreen.
Simple, oppositely arranged, oblong-elliptic to obovate-elliptic (45-100 x 20-60 x 50 mm), stiffly leathery, thick and glabrous leaves, with broadly tapering, sharply pointed tips, held on a thickset, wrinkled petiole of up to 15 mm.
Young leaves are reddish-green, becoming a medium to dark, glossy green, with paler, often purple-red tinged undersides.
The margins are smooth, rolled under, and the lateral veins are prominent, reaching the margins without joining or looping together.
The midribs are conspicuously raised.

Flowers

Dense clusters of strongly scented, five-petalled, tubular flowers.
Each petal (2-3 mm), is white on the inside, pink-tinged on the outside, and the long, slender tubes (8-11 mm), are greenish-pink.
The flowers grow from the leaf axils. (April-November).

Fruit

An oval to almost round (10-20 mm), fleshy, plum-like berry.
The fruits turn from a bright red to a dark, almost purplish-black. (September- February).

Height

Spread

Medicinal

Although the plants are highly toxic, they have various medicinal uses, with the leaves and roots being used, mainly to combat poisoning and parasites.
Dried and powdered leave are used to treat snake and spider bites.
The concoctions are either directly applied to the bite or a paste is made and then applied.
Weak leaf infusions are taken as a tea and are said to be useful in the treatment of headaches, abdominal pains, colds, measles and cases of blood poisoning.
An infusion of the roots is drunk to expel tapeworm, to treat menstrual disorders, and syphilis.
Leaves are desiccated, pulverized, and then snuffed or soaked in water and used as a nasal spray.
Small pieces of the stem are chewed to relieve toothache.

Practical

The bark and wood of the plants have been used in the preparation of poisons, especially arrow poisons, by the Koi-San people.
Chips are steeped in water, then boiled until a sticky, tar-like substance is obtained.
This concoction is then strained and stored for future use.
Pulp from the ripe fruits is said to be edible, and has an acrid, slightly sweetish taste.
It has been used to make preserves and jellies, but care should be taken, as this can be very dangerous.

Warnings

It is recommended that it is not planted near schools, or where children would have access to it, as all parts of the plant are highly poisonous with the possible exception of the ripe fruits.
Fruits may appear ripe while still being unripe, so do not experiment with this plant.
Food prepared over fires kindled from sticks of this tree have proved fatal upon ingestion.

Wildlife

The wonderfully fragrant flowers attract butterflies, bees, and many other insects.
Even though the fruits are toxic when unripe, and fatally poisonous to humans and many animals, many bird species devour the fruit with apparent immunity.
They then disgorge the stones, which germinate freely.

Advantages

A good tree for attracting wildlife to the garden.
It is a good garden subject, withstanding considerable drought and frost, also, responds well to pruning, coppicing and pollarding.
Very decorative, evergreen, tolerant of shade, with a non-aggressive root system, making it the ideal container specimen.
The trees do not grow very big, so they are suited for small and townhouse gardens.
A beautiful focal or accent plant, it can also be used as a screening or hedge plant and makes a good informal shrub border.
Hardy and attractive, with highly fragrant flowers that can be smelled form a great distance away.

Tolerance

Tolerant of a wide range of soil types, flourishing even in very clayish or rocky soils.
Although it grows best in areas with a mean annual rainfall of more than 600mm, established plants are quite tolerant of drought.
Young and recently transplanted plants should always be watered regularly until they become established.
Older, established plants can withstand several degrees of frost, but young plants should be sheltered against extreme cold for at least the first 3 or 4 years.
They are wind resistant.

Growth Rate

Lighting

Soil & Water

Able to flourish in a wide range of soil types, from red clay to sandy or rocky, with a neutral ph.
For the best development, it is recommended to plant it in well-drained, loamy or peaty soil, but it will accept less favourable mediums.
Low to medium water requirement.
Unestablished plants can be given extra water, and more may be given during very hot and dry times.

Propagation

Easily grown from seed collected from ripe fruit or semi-hardwood cuttings harvested from the plant in early or mid-spring.
The seeds require no pre-treatment, but has a very limited viability, so should be sown immediately after harvesting.
Sow in a well-drained, river sand and compost rich mixture, place in a temperate, bright area, and keep the soil moist but do not let it become waterlogged.
Cuttings should be taken from half-ripe, actively growing shoots on the tree, and placed into a similar soil mixture.
They can be treated with a rooting hormone.