Giant Trees Up to 3000 Years Old Found in Tanzanian Rainforest Belong to Previously Unknown Species

A group of botanists has formally described a new species of tree from the mountains of southern Tanzania, and it’s a pretty special one. The species, named Tessmannia princeps, was first encountered during a field survey back in 2019 in the Udzungwa Mountains. Now, after several years of research and documentation, it’s been officially added to the scientific record, thanks to the work of Andrea Bianchi, an Italian botanist specializing in tropical flora, and his colleagues.

The name princeps is Latin for “the first” or “the most prominent,” which fits well. These trees tower above the forest, reaching up to 40 meters tall, making them some of the tallest in their environment. With their tall, straight trunks and broad buttress roots, they stand out in the dense rainforest, both literally and biologically. The trunks can reach up to 2.7 meters in diameter (nearly 9 feet).

At first glance, Tessmannia princeps looks similar to another East African tree species, Tessmannia densiflora. But there are some clear differences. The new species grows much taller and has significantly more leaflets per leaf — up to 48, compared to a maximum of 26 in its relative. It also produces small white flowers instead of red ones and grows in a very specific type of montane rainforest between 1300 and 1500 meters above sea level. These differences, confirmed through fieldwork and herbarium samples, were enough for the researchers to confirm it as a separate species.

The discovery wasn’t limited to just a single tree. When researchers returned to the area, they were able to locate nearly a hundred individuals. In one lucky case, they found a tree that had fallen over naturally, giving them the rare chance to closely examine its structure, including the wood, seeds, and roots — things that are usually hard to study without cutting a tree down.

The tree’s seeds turned out to be particularly interesting. Unlike many of the large rainforest trees that rely on animals to disperse their seeds, Tessmannia princeps has small, hard seeds that are released forcefully when the pod dries and splits open. This type of dispersal is more often seen in smaller trees or those growing in drier habitats. In fact, most of the tree species it shares the forest with produce larger, softer seeds that don’t survive long if they dry out. T. princeps is different in that respect — and this may offer clues about its evolutionary history and how it adapted to its environment.

esearchers also measured the tree’s wood density and found it to be extremely heavy and durable. One clue that might help explain the tree’s impressive size and long life is its slow growth. Although growth rate data is limited, trees of similar structure and wood density are known to grow just a few millimeters in girth per year. Some trees with this growth pattern are believed to live for over a thousand years, or even longer.

Because of its small population size and restricted range, the scientists have assessed Tessmannia princeps as “Vulnerable” under the IUCN Red List criteria. So far, only two subpopulations have been documented, both located within protected village forest reserves in the Udzungwa Mountains. These areas are part of a local forest restoration initiative that includes reforestation efforts and conservation incentives for nearby communities. Without these protections, the species would likely be at much greater risk.

One interesting point raised by the study is that the tree seems to be completely absent from larger, nearby forests like the Uzungwa Scarp Nature Reserve, even though those areas have similar conditions. This led the authors to suggest that Tessmannia princeps may never have been present there at all, rather than being wiped out by logging. That makes its known populations even more important to monitor and protect.

The discovery of this species also contributes to a broader understanding of how the Eastern Arc Mountains connect with other African forest regions, especially those in West and Central Africa. Certain features of Tessmannia princeps resemble species found much farther west, which supports the idea that these humid mountain forests may have once been part of a larger continuous ecosystem.

For now, Tessmannia princeps lives on in two protected forest areas, where cutting down trees is prohibited. But with only around a hundred individuals known to exist, and its habitat limited to a narrow range in a specific kind of rainforest, its future depends heavily on continued protection and support from conservation programs.

It’s not every day that a towering tree species is officially recognized, especially one that might live for millennia. The hope is that now, with a formal name and growing awareness, Tessmannia princeps will have a better chance of staying rooted in the forest for generations to come.