Red Stinkwood (Prunus africana): a multipurpose tree under severe threat

A member of the rose family
Prunus africana belongs to the Rosaceae-family, a large and economically important plant family that also includes almonds, apricots, cherries, plums, peaches and nectarines. In southern Africa, well-known indigenous members of this family include Cliffortia, Leucosidea, Rubus, and Prunus species.
The genus name Prunus originates from the classical Latin word for a plum tree, while the species name africana reflects its distribution across the montane forests of Africa.
Distribution and habitat
Red stinkwood grows naturally on steep mountain slopes, in Afromontane forests, and in evergreen forest ecosystems. Its range extends across a wide geographical area including the Western Cape, Eastern Cape, KwaZulu-Natal, Mpumalanga, Limpopo, Northwest Province, Eswatini, Lesotho, Mozambique, tropical Africa, Madagascar and the Comoros.
This broad distribution illustrates the ecological adaptability of the species, although it is most closely associated with cool, moist montane forest environments.
A tree known by many names
The cultural and ecological importance of Prunus africana is reflected in the many names it carries across different regions and languages. These include African cherry, red stinkwood, African plum, African prune, African almond, ironwood, and bitter almond.
In Afrikaans it is known as rooistinkhout, Afrika-amandel, bitteramandel, or wildekersieboom. African language names include umdumezulu (isiZulu), umkhakhase (isiXhosa) and mulala-maanga (Tshivenda).
These names often reflect the tree’s distinctive characteristics, particularly the strong bitter almond scent produced by the bark, leaves, and freshly cut wood.
Secret extrafloral nectaries
One of the more fascinating biological features of red stinkwood is the presence of extrafloral nectaries. These are small, specialised glands located on plant parts such as leaves or stems rather than within flowers.
Unlike floral nectaries, which attract pollinators, extrafloral nectaries attract protective insects. In Prunus africana, these glands often attract ants, which feed on the nectar produced by the tree. In return, the ants help protect the plant by attacking or deterring herbivorous insects such as caterpillars, aphids and other leaf-eating organisms.
The nectar produced by these glands mainly consists of sugars such as sucrose, glucose and fructose, together with smaller quantities of amino acids, lipids, alkaloids, saponins and flavour compounds. Nectar production can vary depending on environmental factors such as soil quality, water availability, temperature, humidity and daylight. Interestingly, these glands may continue producing nectar even after flowering has ended.
This defensive partnership between plants and insects represents an important ecological adaptation that contributes to ecosystem stability and biodiversity.
A truly multipurpose tree
Red stinkwood produces small, creamy-white, fragrant flowers arranged in dense clusters known as inflorescences. The flowers contain both male and female reproductive structures and are visited by various pollinators including bees and butterflies.
The fruit is a small fleshy drupe containing a single seed. As it ripens it turns from reddish-brown to black. While the fruit is generally too bitter for human consumption, the fleshy outer layer attracts birds, primates and other wildlife, which play an important role in dispersing the seeds.
The tree is highly valued for several reasons:
Medicinal use
For centuries Prunus africana has been used in traditional African medicine. The bark, leaves and fruit release a strong bitter-almond scent when bruised. Mature bark is widely used as an herbal remedy to relieve symptoms associated with an enlarged prostate and other urinary tract conditions. Leaf extracts are sometimes inhaled for fever or infused to stimulate appetite. Bark preparations are also used traditionally to treat stomach ailments, and extracts have been used as purgatives in livestock.
Wood and practical uses
The wood of red stinkwood is heavy, strong, straight-grained and pink in colour, emitting a pungent bitter-almond scent when freshly cut. Once dry, the wood turns a rich mahogany colour and loses its odour. Because of its durability it has historically been used for tool handles, wagons, flooring, furniture and household utensils. It also produces excellent firewood.
Ornamental value
In addition to its practical uses, red stinkwood is also planted as an attractive shade tree in gardens.
Conservation status
Despite its value, Prunus africana is now under serious threat. The global demand for its medicinal bark has led to extensive and often unsustainable harvesting, particularly in parts of central and eastern Africa. Removing bark from the trunk can severely damage or kill the tree, leading to declining populations in some regions.
As a result, the species has been classified as Vulnerable on the IUCN Red Data List and is listed in Appendix II of the Convention on International Trade in Endangered Species (CITES). This means international trade in the species is regulated to ensure that harvesting does not threaten its survival in the wild.
Various conservation initiatives are now promoting sustainable harvesting practices, cultivation programmes, and improved regulation of trade. These efforts aim to ensure that this remarkable African tree continues to survive and provide ecological, medicinal and cultural benefits for generations to come.