Description & Interesting Facts:

Bushman's Poison, Boesmansgif, inHlungunyemb, iNtlungunyembe  (Acokanthera oppositifolia) is an exceptionally attractive, medium to large tree or woody shrub (SA Tree No: 639). It grows wild in Limpopo, North West, Gauteng, Mpumalanga, KwaZulu-Natal, and in the Western and Eastern Cape.

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 grasslands

Bushman's poison It is one of three South African members of the genus Acokanthera, and belongs to the same family as many popular subtropical ornamental plants such as the Impala Lily (Adenium multiflorum)and Natal Plum or Num-num (Carissa macrocarpa),as well as exotics like Frangipani, Allamanda and Oleander.

This family is characterized by having very sweetly scented flowers and a sticky milky sap which is poisonous. The name Acokanthera is derived from the Greek and refers to the sharp anthers of the flowers. The species name oppositifolia refers to the opposite arrangement of the leaves.

Depending on climate and rainfall, bushman’s poison will grow moderately to a height of 2 to 7m with a spread of 1.5 to 2.5m. The main stem is typically short, with many upward growing branches and brown bark which becomes deeply grooved with age.  Young leaves are reddish-green, becoming a medium to dark, glossy green, with sharply-pointed tips and paler, often purple-red tinged undersides.

Butterflies are attracted to the dense clusters of white to pink-tinged, very sweetly-scented flowers which appear anytime from June to October, depending on the climate of your region. The large plum-coloured berry-like fruits are relished by birds.

Bushmans Poison. Picture courtesy Random Harvest NurseryUses:

All parts of the plant are highly poisonous with the possible exception of the ripe fruits. The milky sap was widely used by the Khoisan to form part of the cocktail used to poison the tips of their arrows for hunting.

Although the plants are highly toxic, traditionally, in its native regions it has various medicinal applications. It is used to treat snake and spider bites, intestinal worms, headaches, inflammations, colds, fever and even malaria.

In the Garden:

Although poisonous, bushman’s poison is safe to touch and is certainly a worthy garden subject.  It is also pest and disease-free, requiring minimal maintenance in the garden.  

The highly fragrant flowers can be smelled from a great distance away, and its non-aggressive root system makes it perfect for gardens large and small, and it even grows well in a pot.

If pruned regularly it makes an excellent hedging plant, and because it is wind resistant it’s also a great windbreak. For a hedge or windbreak plant 2 to 3m apart.

Bushman’s poison is easy to grow in shade to sun and is perfect for wetland and marsh gardens. And although it likes to be watered moderately, once established it is also remarkably water-wise, saving you a fortune on water bills.

Because the flowers attract a host of pollinators like bees and butterflies, and birds relish the fruits, bushman’s poison is invaluable in wildlife gardens.

Acokanthera oppositifolia Picture courtesy Random Harvest NurseryCultivation:

This species is widespread over many parts of the country with the exception of the drier parts, and those extremely cold areas.

Is bushman's poison hardy to frost and cold?

Bushman’s poison is quite hardy to frost and cold, with mature plants know to tolerate short spells when temperatures drop as low as -1°C. Young plants should be sheltered against extreme cold for at least the first 3 or 4 years.

In areas with severely cold winters pot culture is recommended, and it is advisable to move the container to a protected area during winter, and to protect the roots from the frost. Wrapping the pots with bubble wrap is a great insulator.

How much sun does bushman’s poison require?

The plant grows well in in sun, semi-shade or shade, but it does better with some shade, or half day, morning or afternoon sun.

What soil does bushman’s poison require?

Bushman’s poison is able to flourish in a wide range of soil types, from red clay to sandy or rocky soils, with a neutral pH, thriving in loamy or peaty soil. For good growth, add generous amounts of compost to the planting hole.

Does bushman’s poison need fertilising?

If planted in fertile soil the tree does not need feeding, but can be fed seasonally with a balanced organic fertiliser, together with mulch around the roots. Potted plants will respond well to regular feeding during spring and summer.

How much water does bushman’s poison need?

Although it grows best in areas with a mean annual rainfall of more than 600mm, mature plants are very water-wise and quite tolerant of drought. To keep the plant looking at its best in the garden, water moderately during long, hot and dry spells.  Water young plants regularly until they are established.

Propagation:

Propagation of this species is from seeds which are available online. Fresh seed collected from ripe fruit requires no pre-treatment, but has a very limited viability, and should be sown immediately after harvesting. Sow in a well-drained, river sand and compost mixture. Place in a warm, bright area, and keep the soil moist but do not let it become waterlogged.

 Semi-hardwood cuttings are taken from September to October from half-ripe, actively growing shoots.  They can be treated with a rooting hormone before being planted into a well-drained, river sand and compost mixture.

Caution:

All plants of the genus Acokanthera exude a milky latex which contains toxic cardiac glycosides strong enough to cause death. All parts of the plant are poisonous, with the possible exception of the ripe fruits.

Food prepared over fires kindled from the sticks of this tree, have proved fatal upon ingestion.