2 Trees Twice Thought to Be Extinct Rediscovered in Tanzania

Join Our Community of Science Lovers!

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


How's this for luck? Two tree species that scientists believed were extinct—twice—have been rediscovered in a remote area of Tanzania.

According to a paper published in the Journal of East African Natural History, the two species were rediscovered in the remote, highly fragmented and rarely explored Namatimbili–Ngarama Forest, 35 kilometers inland from the Indian Ocean.

Erythrina schliebenii had only been known from two samples collected near Lake Lutamba in the 1930s, an area that has since been clear-cut. A specimen was rediscovered in a tiny patch of forest in 2001, but a Dutch company cleared the area to create a biofuel plantation in 2008.


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


The second tree, Karomia gigas, was first discovered in 1977 when a specimen was observed in Kenya's Mwara Kaya sacred forest. It was only seen one other time, in 1993, 600 kilometers away in Tanzania. The initial specimen was chopped down a few years after it was identified, and the second has since also been lost.

"The rediscovery of these two trees highlights the lack of information in a forested region where we could be losing species without ever knowing they are there," co-author Neil Burgess, senior advisor to the World Wildlife Fund's (WWF) conservation and Africa program, said in a prepared statement. "Conservation of these forests, in partnership with local villages, is essential. This can also lead to standing forest being used as an income source for communities through the development of sustainable logging initiatives."

According to the WWF, the coastal forests where these trees were rediscovered are increasingly fragmented or cleared as the area's human population grows and expands. "Erythrina schliebenii has only survived because it grows in rocky areas that are not usually cleared for cultivation, but even those areas will be cleared one day if nothing is done," said co-author Cosmas Mligo, a botanist from the University of Dar es Salaam.

Exact counts of these trees are still not available, but the authors estimated the population of each at fewer than 50 individuals and warn that they remain critically endangered.

Photo 1: Erythrina schliebenii, courtesy of WWF. Photo 2: Co-author Cosmas Mligo with a leaf and twig of Karomia gigas, © Cosmas Mligo, used with permission

John R. Platt is the editor of The Revelator. An award-winning environmental journalist, his work has appeared in Scientific American, Audubon, Motherboard, and numerous other magazines and publications. His "Extinction Countdown" column has run continuously since 2004 and has covered news and science related to more than 1,000 endangered species. John lives on the outskirts of Portland, Ore., where he finds himself surrounded by animals and cartoonists.

More by John R. Platt

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe