The Rediscovery of Begonia larorum on Alcatrazes Island: Ending a Century of Absence

Off the coast of São Paulo, Brazil, scientists have officially confirmed the remarkable reappearance of Begonia larorum, a plant species found nowhere else but the Alcatrazes archipelago. This botanical treasure had vanished from scientific records for over a century, with the last documented collection dating back to the 1920s by the German zoologist Hermann Luederwaldt. The breakthrough came as part of a systematic effort to update the island's floral inventory, a project launched in 2022 with the vital financial backing of the São Paulo Research Foundation (Fapesp).

The turning point in this botanical mystery occurred in February 2024 during one of fourteen expeditions conducted through September of that year. Researchers initially located a single, sterile specimen tucked away in the island's understory, requiring meticulous comparison with historical descriptions to confirm its identity. By September 2024, the team discovered a small but thriving population of 19 individuals, 17 of which were in their reproductive phase. To safeguard the species' future, scientists including doctoral candidate Gabriel Sabino and Professor Fabio Pinheiro from the University of Campinas (Unicamp) have initiated laboratory cloning for ex-situ conservation.

Experts believe that the survival of B. larorum is a direct result of the extreme isolation and the nearly inaccessible nature of the terrain where it was rediscovered. Alcatrazes Island served as a target for Brazilian Navy artillery exercises until 2016, enduring devastating fires that likely pushed the begonia into these remote, protected pockets. The study revealed that B. larorum has evolved unique traits to survive these harsh conditions, including a high tolerance for water scarcity, robust root systems, and a rupicolous habit of growing directly on rocks. Unlike its mainland relatives, this species also features notably smoother leaves.

These significant findings were detailed in a peer-reviewed article published in Oryx The International Journal of Conservation in October 2025. Given the extremely restricted range and the tiny population size, the research team has recommended that the species be classified as Critically Endangered according to the IUCN Red List. The Alcatrazes archipelago, situated approximately 35 kilometers from the mainland, is currently managed as part of an ICMBio conservation zone, encompassing both the Alcatrazes Archipelago Wildlife Refuge and the Tupinambás Ecological Station.

The rediscovery of Begonia larorum after a hundred years of obscurity highlights the critical need to protect the complex environmental conditions that allowed it to endure. This event marks the beginning of a new chapter in conservation, with future research slated to focus on the plant's genetics, pollination mechanisms, and evolutionary adaptations. By deepening our understanding of its ecology, scientists hope to ensure that this resilient species never fades into the shadows of extinction again.