There is a tree growing across tropical Africa that most people in the countries where it grows have never heard of — and yet, for decades, its seeds were leaving West African ports by the hundreds of tonnes every year, bound for pharmaceutical laboratories in Germany, and later in China and India. I find that quietly astonishing. Voacanga africana is not a plant that ever really belonged to a local market. It was catalogued by colonial botanists, typed by chemists, and shipped out. The people living near it were not the buyers. That story, of a plant moving from forest to pharmaceutical supply chain while essentially bypassing the communities it grew among, is worth telling properly.
The seeds arrive looking unremarkable — small, pale, slightly wrinkled, with very little scent at room temperature. Nothing about them announces a century of international trade. But the chemistry inside them is genuinely unusual, and the history of how that chemistry was discovered, named and then exported is one of the more interesting chapters in West African botanical history. This is that chapter.
Key takeaways
- Voacanga africana is a tree native to a vast belt of tropical Africa, formally described by British botanist Otto Stapf in 1894 and still being taxonomically clarified today.
- Its seeds and bark contain a group of compounds called monoterpenoid indole alkaloids — including voacangine and tabersonine — which drove decades of pharmaceutical export trade.
- Export data from Ghana show an average of over 600 tonnes of seeds leaving the country per year between 2005 and 2013, almost none of it sold domestically.
- The seeds are now recognised as a more sustainable harvest source than bark or root, because collecting them does not require felling or stripping the tree.
What Voacanga africana actually is
Voacanga africana is a small tree or large shrub in the family Apocynaceae — the same family as oleander, frangipani and the periwinkle. That family connection matters, because Apocynaceae are well known across botany for producing complex alkaloids, and V. africana is no exception. It grows across an extraordinary sweep of tropical Africa: the Royal Botanic Gardens, Kew records its native range as spanning Angola, Benin, Cameroon, Congo, DR Congo, Gabon, Ghana, Guinea, Ivory Coast, Kenya, Liberia, Mali, Mozambique, Nigeria, Senegal, Sierra Leone, Tanzania, Togo, Uganda, Zambia and Zimbabwe, among others — with an introduced population reaching as far as south-central China.
The tree tends toward forest margins and secondary growth, the kind of vegetation that fills in where primary forest has been disturbed. It is not a deep-canopy species. It likes light, tolerates seasonal dry periods, and is most common in the seasonally dry tropical biome rather than in the wet forest interior.
The flowers are white or pale yellow, five-petalled, and fragrant in the way that many Apocynaceae flowers are — honeybees are documented floral visitors, with a doctoral study from Ngaoundéré in Cameroon recording Apis mellifera adansonii foraging specifically on V. africana flowers. The fruit that follows is a paired, rounded capsule, bright green and distinctive in the canopy. Inside are the seeds: small, brown, embedded in an orange-yellow pulp that stains whatever it touches.
The naming history is, to put it mildly, a mess. Kew’s taxonomic record lists nineteen accepted synonyms — nineteen separate names given by different botanists working from specimens in Sierra Leone, Congo, Tanzania and elsewhere, who each thought they had found something new. They had not. They had found the same wide-ranging, variable tree and named it independently.
Untangling that took most of the twentieth century, and it is still not entirely finished: a 2024 paper in Kew Bulletin formally described a new sister species, Voacanga madureirae, from specimens collected in Príncipe, Bioko and western Cameroon that had been sitting in herbaria misidentified as V. africana for years. I find that satisfying rather than troubling — it is a reminder that even heavily studied plants still have things to say.
The species was formally named and described in 1894 by Otto Stapf, a British botanist working at Kew during the height of colonial botanical survey activity in West and Central Africa. Stapf described a great many species in that period; he was methodical and prolific. What he could not have anticipated was that the tree he was cataloguing would, half a century later, become a bulk export commodity for the global pharmaceutical industry.
If you want to read our article on what Picralima nitida actually looks like from tree to powder, it is a useful companion piece — another Apocynaceae with a similarly complex alkaloid profile and a similarly tangled history of botanical naming.
The chemistry: what makes these seeds unusual
The reason pharmaceutical buyers were prepared to ship hundreds of tonnes of these seeds out of West Africa is straightforward: the seeds, and more particularly the bark, contain a class of compounds called monoterpenoid indole alkaloids. Alkaloids are nitrogen-containing molecules produced by plants — caffeine is one, morphine is one, quinine is one. The indole alkaloids found in Voacanga africana are structurally more complex than any of those, and that complexity is what made them interesting to synthetic chemists.
The alkaloid profile varies significantly depending on which part of the plant you are looking at. Burkill’s Useful Plants of West Tropical Africa, compiled from colonial-era and mid-twentieth-century records, gives the concentrations plainly: root bark runs at five to ten per cent alkaloids by dry weight, stem bark at four to five per cent, seeds at around one and a half per cent, and leaves at a fraction of that. The seeds contain less, but they are much easier to collect without damaging or killing the tree.
The principal alkaloids named across the literature include voacamine, voacangine, voacristine, vobasine and tabersonine. Voacangine is structurally related to ibogaine — a compound found in a different but related West African plant, Tabernanthe iboga — and that structural relationship is part of what drove the pharmaceutical interest. The seeds are documented to contain tabersonine as their major alkaloid constituent, with ibogaine recorded in the bark. A 2024 phytochemistry study isolated fifteen monoterpenoid indole alkaloids from the stem bark alone, twelve of which had not previously been reported from the genus at all. That is a meaningful finding for a plant that has been under chemical investigation for sixty years.
What I find genuinely interesting about the chemistry is the spatial variation — different alkaloids concentrating in different tissues, in different proportions, for reasons that are not entirely understood. The same seed from the same tree in Ghana will produce a different alkaloid fingerprint depending on when it was harvested and how it was dried. Analytical chemists have used LC/MS — liquid chromatography coupled to mass spectrometry, a technique for separating and identifying compounds in a mixture — to classify commercial seed batches into distinct chemical types, which suggests the variation is real and consistent rather than noise.
| Compound | Type | Plant part |
|---|---|---|
| Voacangine | Monoterpenoid indole alkaloid | Bark, seeds |
| Voacamine | Monoterpenoid indole alkaloid (principal) | Bark |
| Tabersonine | Monoterpenoid indole alkaloid | Seeds (major constituent) |
| Voacristine | Monoterpenoid indole alkaloid | Bark |
| Vobasine | Monoterpenoid indole alkaloid | Bark |
| β-sitosterol | Phytosterol | Various |
We also stock organic Voacanga africana root bark powder for those who want the bark rather than the seeds, and the alkaloid profiles of the two are meaningfully different, as the numbers above suggest.
African Botanicals: The Quick Reference Guide
181 plants of the African materia medica. Each entry gives you the botanical name, the family and range, the part used, and the characters that separate that plant from the things it gets confused with — leaf arrangement, latex, scent, taste, pod shape. Then what tradition uses it for, and the cautions that matter: the interactions, the protected and CITES-listed species, the lookalikes that aren’t safe.
A fascinating record of African plants and their uses
Colonial botany and the pharmaceutical trade: who was buying, and why
The formal botanical description in 1894 was the beginning, not the end. For the first half of the twentieth century, Voacanga africana sat in herbaria and colonial botanical reports as a catalogued species — noted, named, filed. The trade history really begins in the mid-twentieth century, when European pharmaceutical chemists became seriously interested in indole alkaloids as starting materials for synthesis. The structural complexity that made these molecules difficult to build from scratch in a lab made them extremely valuable when they could be extracted directly from plant material.
What followed was a supply chain that looked, from one end, like a bulk commodity trade. Seeds were gathered, dried, bagged and exported. Export data compiled from ASNAPP figures for Ghana show an average of 616.67 tonnes of seeds exported per year between 2005 and 2013. That is not a niche botanical curiosity — that is an industrial raw material. And almost none of it touched the domestic market. A quantitative survey of Ghana’s herbal trade found that Voacanga seeds move through export channels rather than local retail. The plant was grown near communities who had no particular use for it in that form, harvested by gatherers paid for the weight, and shipped to buyers thousands of miles away who used it for purposes those gatherers would have had no reason to know about.
The destination of that trade has shifted over the decades. German buyers dominated in the 1980s. By the 2000s and into the 2010s, the buyers were increasingly in China and India — countries building large pharmaceutical and nutraceutical manufacturing industries that needed the same alkaloid starting materials the European labs had wanted a generation earlier. The plant did not change. The geopolitics of who controlled the synthesis did.
There is a parallel here with other West African botanical exports that I keep coming back to. We covered the seeds men traditionally carried on long hunts across West Africa in an earlier piece, and the contrast is pointed: some plants have deep local histories of use and a secondary export trade layered on top. Voacanga africana went almost directly to export, with the local cultural relationship remaining thin by comparison. That asymmetry is worth noticing.
The Voacanga africana root bark chips we stock come from the same supply networks that feed this broader trade, but sourced directly and handled properly — which matters more than it might sound, given the variation in alkaloid content depending on processing.
Names, regions, and the confusion they cause
One of the things that struck me early on when researching this plant is how thin the vernacular name record is compared to plants with deep local use histories. Burkill’s compilation gives regional common names across Sierra Leone, Ivory Coast, Ghana, Senegal and Congo, but they are scattered and inconsistent — different language groups across its vast range gave it different names, and in many areas it appears to have been identified primarily by botanists and traders rather than by communities building a lexicon around it. That is itself a kind of data about the plant’s relationship to the people who lived alongside it.
The genus name, Voacanga, derives from the vernacular name used in Madagascar for a related species — which is already a sign of the taxonomic confusion that would follow, since the African species was effectively named by reference to an island it does not grow on. Africana simply means of Africa, which, given that the species grows across thirty or more African countries, is about as specific as naming a tree “the European one”.
The confusion between Voacanga africana and its close relatives is not merely academic. In trade, related species have been sold as or alongside V. africana. The 2024 discovery of V. madureirae as a distinct species — separated from specimens that had been filed as V. africana for years — suggests that some of what entered the export trade under that name may have been mixed. Analytical chemists have noted that commercial seed batches divide into distinct chemical types, which is consistent with mixed sourcing. When I source these seeds I pay attention to provenance precisely because the genus is wide and the naming is loose.
The Apocynaceae family, which this tree belongs to, has a history of this kind of naming complexity. I have written a piece on how to tell apart the Hibiscus species that people constantly confuse, and the structural problem — a large, widespread genus where regional populations look slightly different and got named by different people — is remarkably similar.
Harvesting, sustainability and what the seeds actually look like
The most significant practical fact about Voacanga africana in the current context is that intensive harvesting has made it locally scarce in parts of its range. An ethnobotanical field survey from Fundong in the Northwest Region of Cameroon noted plainly that the species had become rare in the area of study due to the intensity of harvesting pressure for external trade. That is a direct ecological consequence of the export trade — a plant disappearing from local landscapes because the demand is entirely external.
Seeds are now understood by researchers to be a more sustainable harvest form than bark or root. A peer-reviewed analytical chemistry paper from PMC frames this directly: seeds are a renewable resource that can furnish access to the alkaloids that would otherwise only be obtained from root or aerial parts, the harvest of which may be destructive to the plant or threaten its viability. Stripping bark or digging roots kills or severely damages the tree. Collecting ripe seeds does not, provided the harvest is not so intensive that no seeds remain to regenerate the population.
What do the seeds actually look like? They are small — roughly the size of a large apple pip — pale to mid-brown, with a faintly wrinkled surface and a slight sheen when fresh. In bulk they have a very faint, slightly resinous smell, nothing dramatic. The orange-yellow pulp that surrounds them in the fruit does not survive commercial processing; by the time they arrive as a dried product they are dry, clean and odourless at ambient temperature. Grinding them releases a faint woody, slightly resinous note that I find hard to characterise precisely — it is not unpleasant, just unfamiliar.
If the seed story interests you, the parallel with Griffonia simplicifolia seeds is worth noting — another West African seed that moved through similar export channels for similar reasons, and that appears alongside Voacanga in the same trade surveys. Same region, same export logic, same dynamics.
Frequently asked questions
What is Voacanga africana used for?
Voacanga africana seeds and bark have been exported in bulk as raw materials for the pharmaceutical and nutraceutical industries, primarily because of their content of complex alkaloids — including voacangine and tabersonine — that serve as starting materials for chemical synthesis. The plant has also been documented in ethnobotanical surveys across its West and Central African range, though its primary commercial role has been as an export crop rather than a local remedy or food.
How much voacangine is in Voacanga africana seeds?
Alkaloid concentration varies considerably by plant part. Historical records compiled by Burkill give seeds at around one and a half per cent total alkaloids by dry weight, compared to five to ten per cent in root bark and four to five per cent in stem bark. Voacangine is one of several alkaloids present; tabersonine is documented as the major alkaloid constituent specifically in the seeds. The exact voacangine fraction within that seed alkaloid total varies by batch, provenance and analytical method.
Is Voacanga africana the same as iboga?
No. Voacanga africana and Tabernanthe iboga are distinct species within the Apocynaceae family. They are related, and their alkaloid profiles overlap structurally — voacangine, found in V. africana, is chemically related to ibogaine, found in T. iboga. That structural relationship is why the two plants are often mentioned together in chemical literature. But they are different trees, growing in somewhat different parts of tropical Africa, with different alkaloid profiles overall.
Is Voacanga africana legal?
Voacanga africana itself — as a plant, seed or bark — is not a controlled substance in the United Kingdom, the European Union or the United States as of the time of writing. It is sold legally as a botanical. Some of its isolated alkaloids, or compounds derived from them through synthesis, may be subject to separate controls depending on jurisdiction. If you are in any doubt about the regulations that apply to you, consult the relevant authority in your country. We sell the seeds as a botanical material, not as a pharmaceutical product.
Where does Voacanga africana grow?
Voacanga africana is native to a very wide belt of tropical Africa — from Senegal and Guinea in the west, through Nigeria, Ghana, Ivory Coast and Cameroon in the centre, and extending east into Kenya, Tanzania and Uganda, and south into Angola, Zambia and Zimbabwe. It grows primarily in forest margins and secondary vegetation in seasonally dry tropical biomes. An introduced population also exists in south-central China, a legacy of the plant’s role in pharmaceutical supply chains.
There are very few plants whose story runs from a Victorian herbarium in London to a container port in Tema to a pharmaceutical lab in Shanghai — and Voacanga africana is one of them. The seeds you see in our 50g bags are the same material that has been moving through those channels, at scale, for the better part of a century. Understanding that history changes how you look at something that otherwise just sits quietly in a paper bag. The botany is interesting. The chemistry is genuinely unusual. And the trade story is one I think more people in West Africa, and more people interested in West African plants, should know about.
Shop organic Voacanga africana seeds at Jostylin Naturals
Sources
- Royal Botanic Gardens, Kew, 2024. Voacanga africana Stapf — Plants of the World Online. powo.science.kew.org.
- Burkill, H.M., 1985. Voacanga africana Stapf [family APOCYNACEAE] — Useful Plants of West Tropical Africa, Vol. 1. JSTOR Global Plants / Royal Botanic Gardens, Kew.
- Paiva, O., Lachenaud, O. & Covelo, 2024. Voacanga madureirae (Apocynaceae), a new species from Atlantic Central Africa. Kew Bulletin, Springer.
- ScienceDirect Topics, 2024. Voacanga — topic overview, export data and alkaloid profiles. ScienceDirect / ASNAPP trade data.
- PMC, 2023. Investigation of small-molecule constituents in Voacanga africana seeds and mapping of their spatial distributions using LADI-MS. PubMed Central.
- Biochemical Systematics and Ecology, 2024. Monoterpenoid indole alkaloids from the stem barks of Voacanga africana and their chemotaxonomic significance. ScienceDirect.
- PMC, 2009. Ethnobotanical survey of trees in Fundong, Northwest Region, Cameroon. PubMed Central.
Written by Joanna, founder of Jostylin Naturals. Joanna has worked with West African botanical materials for over fifteen years, sourcing directly from growers and gatherers across the region. This article is for informational and educational purposes only and does not constitute medical advice.
