16 March 2021

From the mountains of Africa: a new to science chimpanzee tree

A tree species, found in Cameroon and Nigeria, has just been scientifically named and it's favoured by chimps.

Two chimpanzees swinging in the trees

Newly named for science, Deinbollia onanae (Sapindaceae), is a montane forest tree species related to the litchi (or lychee), in the remnant highland forests of Cameroon and Nigeria.

It produces black, sweet and sour tasting fruits that are consumed by a rare subspecies of chimpanzee.

The chimpanzees disperse the seeds, by spitting or defecating them, but also use the trees for making their nests. 

The newly named tree species Deinbollia
Species new to science Deinbollia onanae © Matt Walters.

The known unknown

The tree was first suspected of being a new species (“Deinbollia sp. 2”) in Cameroon over 20 years ago, but the initiative to assemble the morphological taxonomic data to formally publish it, only arrived recently. 

It was realised that it is highly threatened, likely Endangered, being found in just five poorly protected forest patches that are widely separated from each other by tens of kilometres of secondary grassland, resulting from slash-and-burn agriculture. 

Researchers sat in a field
Dr Jean Michel Onana who the tree is named after © Y Harvey.

The species is named for Jean Michel Onana, co-author of the Red Data Book of the Plants of Cameroon (2011) and a leading researcher in plant conservation in the country which has the highest plant species diversity per degree square in tropical Africa, many of which are threatened with extinction.

Jean Michel led the IRAD-National Herbarium of Cameroon, Kew’s main partner in the country, for many years and is a taxonomic specialist in the frankincense family, Burseraceae. He is also co-chair of CARLA, IUCN’s Central African Red List Authority.

Ngel Nyaki chimpanzees

Detailed data on the dispersal and other aspects of the ecology of the tree are only known from the Nigerian side of the border at Ngel Nyaki, thanks to the extraordinarily dynamic research team of Hazel Chapman’s Nigerian Montane Forest project.

Here the tree had previously been misidentified as the common widespread lowland species, Deinbollia pinnata.

Although the seeds of the tree are dispersed by chimpanzees, published studies show that they only do so within the Nigerian forest patch and that they do not traverse the grasslands, to other forest areas from which chimpanzees have been lost due to hunting. 

Young chimpanzee staring
Rare subspecies of chimpanzee: the Nigeria-Cameroon chimpanzee © Paul Dutton.

Medicinal bark

In Nigeria, the name for Deinbollia onanae is Jellahi (Fulfude language) and Fulfude speakers (Fulanis) use the bark of this species as medicine to treat stomach aches as well as an anti-helminthic (antiparasitic). 

Now that this tree has been formally named, it can be added to the IUCN Red List and included in one, or more, Tropical Important Plant Areas (TIPAs), which are currently being evidenced as part of Kew’s Cameroon TIPAs programme, meaning its protection is now much more likely. 

Cloudy forest Cameroon

Tropical Important Plant Areas (TIPAs) in Cameroon

Identifying and promoting the long-term conservation and sustainable management of Cameroon’s most important sites for plant diversity.

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