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.
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