New Panama tree species identified after 25 years is already endangered

Andrew Zinin

lead editor

Meet our editorial team
Behind our editorial process
Editors' notes

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:

fact-checked

trusted source

proofread

The GIST
Add as preferred source

In 2000, a group of STRI botanists collected samples of all the plants from the genus Clusia they could find in Panama to find out how the different species in this group are related.

Twenty-five years later, one of the plant samples they collected in the Ngäbe-Buglé Indigenous comarca in western Panama has been formally named as a new species.

But how is it possible that this newly named endemic species is already considered critically endangered?

In a scientific paper published in Kew Bulletin, "Tidying up the small-leaved Clusia taxonomy: description of Clusia nanophylla (Clusiaceae), a new tree species from Panama and comments on its previously used names," STRI botanist and taxonomy specialist Jorge Aranda and his co-authors describe the new species, named for having the smallest leaves registered within the genus—"nano" means small, and "phylla" leaf.

"It wasn't until around 23 years later that we realized we might have a new and highly endemic species on our hands," explained Aranda, who is the Clusia expert in Panama, and who created a Clusiarium in STRI's Gamboa Plant Physiology facilities, a collection of different species of the genus grown in one place for botanical studies. "But the next time we went to the place where the original plant was collected, there were only a few trees left out of the many we had seen the first time."

Clusia nanophylla is one of the most recent species described within the genus that already contains more than 320 species in tropical America, and around 42 species in Panama, across most climates, from drier lowlands to humid premontane areas. "In Panama, in less than ten or twenty meters, you can encounter up to ten species, which is more species of Clusia than in any other place," says Aranda.

Commonly known as copé or copey, Clusia plants and trees are easily recognized by their shiny, fleshy leaves growing opposite to one another, the milky yellow latex that oozes out of their stems, and the star-shaped fruits containing yellow seeds wrapped up in an orange fleshy cover or aril. Birds are attracted to this orange aril, and they spread the seeds by eating and pooping them out, helping with the dispersion of the genus across the region.

The genus Clusia is also special because some species switch from regular photosynthesis, involving uptake of carbon dioxide during daylight hours, to a modified photosynthetic pathway known as CAM (Crassulacean acid metabolism) photosynthesis, which is characterized by uptake of carbon dioxide at night and is typically found in succulent desert plants.

"The Clusias are the only trees in the plant kingdom that are capable of fixing carbon dioxide at night," explains STRI staff scientist Klaus Winter, who studies the ability of plants to perform the water-efficient nighttime CAM photosynthesis instead of normal photosynthesis during the day (C3), including tree species of Clusia that can reversibly switch between the two pathways of photosynthesis.

"Some species perform normal photosynthesis, some almost always fix carbon dioxide at night like a desert cactus, and some species can switch from daytime fixation to nighttime fixation and vice versa, depending on the season and on soil water availability," Winter explains. The ability to switch between C3 and CAM, discovered early in Winter's research career, is one of the finest examples of metabolic flexibility in the plant kingdom. Studying plants that do this can help scientists understand how plants adjust to changing and extreme environmental conditions, such as droughts.

Discover the latest in science, tech, and space with over 100,000 subscribers who rely on Phys.org for daily insights. Sign up for our free newsletter and get updates on breakthroughs, innovations, and research that matter—daily or weekly.

Subscribe

"We have not yet studied the photosynthetic pathway of Clusia nanophylla, the newly named species," said Klaus Winter, "but we predict that it will be a normal C3 plant."

When Clusia nanophylla samples were collected in 2000 as part of a project by STRI postdoctoral researcher Hans Gehrig, there were many specimens found in the premontane area of Cerro Colorado, in the region between Hato Chamí and Hato Ratón.

Aranda and the STRI herbarium team consulted with two world-renowned Clusiaceae experts: plant taxonomist Manuel Luján from the Royal Kew Gardens, a previous short-term fellow at STRI, and curator emeritus researcher Barry Hammel from the Missouri Botanical Gardens, who previously collected plants in the same area in the comarca and provided essential observations on the genus. Luján and Hammel helped determine that the tree was a species that had yet to be given a scientific name.

Aranda and STRI research technician Ernesto Campos-Pineda worked on the process of describing the species, dissecting and measuring and averaging the sizes of everything from the leaves to the fruits and flowers.

But part of the process includes going back to the site and collecting more samples; when Aranda and the other researchers went back to Cerro Colorado in 2024, only about five trees remained. All the others were gone, likely cut down to make way for roads and cattle pastures.

According to the International Union for Conservation of Nature (IUCN), Clusia nanophylla could be classified as endangered, which could help organizations such as Panama's Ministry of Environment (MiAmbiente) to promote its conservation. Right now, the area where this species is found is not an officially protected forest. Official measures could protect the species from deforestation and keep it from disappearing completely.

Aranda highlights that it is essential to have more botanists working on collecting, identifying, and the taxonomic classification of new species of plants, and growing the collections in the STRI herbarium and other reference herbariums.

"It's an arduous process, and it takes a lot of time, from collecting samples with all the plant parts, such as the flowers and fruits, measuring everything and describing every aspect of the plant," explains Aranda. "However, the more plants we identify and add to the collections, the better we can understand the true breadth of the plant biodiversity in the country." The team hopes their work will inspire taxonomists across the tropics to keep discovering new plant species in their own countries.

More information

Jorge Aranda et al, Tidying up the small-leaved Clusia taxonomy: description of Clusia nanophylla (Clusiaceae), a new tree species from Panama and comments on its previously used names, Kew Bulletin (2025). DOI: 10.1007/s12225-025-10287-8

Key concepts

endemic species

Provided by Smithsonian Tropical Research Institute