Researchers from the Rio de Janeiro Botanical Garden describe a new plant species from Madagascar

In 2016, during his doctorate, researcher Leandro Jorge Telles Cardoso found an intriguing plant in the herbarium of the Muséum national d'Histoire naturelle in Paris that didn't look like any of the known species for the group of plants he was studying.

A photo of the same plant, posted in 2018, caught his attention and that of his advisor, João Marcelo Alvarenga Braga. The two researchers decided to investigate this record further and concluded that it was indeed a new species for science.

The photo that intrigued the researchers was posted on the INaturalist network in 2018, the year Leandro was completing his doctorate. Familiar with the parasitic plant family Balanophoraceae, the subject of his master's and doctorate at the National School of Tropical Botany of the Rio de Janeiro Botanical Garden (ENBT/JBRJ), Leandro was able to confirm the occurrence of characteristics that helped to circumscribe a new species, collected and recorded in museum collections for the first time only in 1986!

The photo was taken by collaborator Neek Helme to the west of the Masoala peninsula, in the northeast of the island of Madagascar, in Africa, more than 9,000 km away from Rio de Janeiro, in a location very close to the records analyzed by Leandro at the French museum. During the study to confirm the identity of the new species, the researchers analyzed more than 300 exsiccates (plant samples) in European, American, African and Brazilian herbaria, as well as many images and searches for living plants, covering all species of the Thonningia and Langsdorffia genera.

Named Thonningia alba, the species was described in an article published in January 2024 in the Kew Bulletin. T. alba is a plant that parasitizes the roots of other plants and, as far as is known, is endemic (exclusive) to the rainforests of that region of Madagascar, one of the most biodiverse and threatened places on the planet.

Few samples of T. alba have been found to date - only four records have been identified, in the P (National Museum of Natural History in Paris) and MO (Missouri Botanical Garden - USA) herbaria. This, together with the possible loss of habitat due to the growing human occupation of the Masoala peninsula, has led researchers to consider the species, in an initial assessment, as Endangered (EN) according to the categories of the International Union for Conservation of Nature (IUCN).

In Africa, some species of the Balanophoraceae family are used in traditional medicine and serve as food for humans and other primates, such as bonobos and lemurs. The family now has five genera and seven species recorded on the continent, four of them in Madagascar. But Brazil is the country with the greatest wealth of Balanophoraceae in the world, with six genera and 15 species. Leandro Cardoso, currently a collaborating researcher at JBRJ, is coordinating a research project on this family, which occurs throughout Brazil.