New checklist catalogs every vascular plant in the Americas

A team of 24 researchers pulled together information from plant checklists across the two continents.

Scientists have compiled a list of every known vascular plant found in North and South America, providing a new tool to understand how species are distributed throughout the two continents.

“This is the first time we have a complete overview of the plants of the Americas,” Carmen Ulloa, a botanist with the Missouri Botanical Garden in the U.S., said in a statement. “It represents not only hundreds of years of plant collecting, and botanical research, but 6,164 botanists who described species that appear on this list.”

Beginning in 2015, Ulloa led a team of 24 researchers who pulled together information from plant checklists across the two continents, using a database at the Missouri Botanical Garden called Tropicos to stockpile the incoming data.

With the details of all of the species in one place — which involved adding more than 25,000 new plants to Tropicos — scientists now have a public, searchable checklist with nearly 125,000 species. The team published their report in the journal Science on Dec. 22.

Some 355 plant families are represented. The two continents contain 33 percent of the species of the world’s vascular plants, which include coniferous trees, ferns and flowering plants. Most are found in only one country or region. South America is home to about 65 percent of the plants on the new checklist, and only 8,300 species are found on both continents.

Ulloa and her colleagues anticipate that the database will continue to grow. They found that scientists have been describing 744 new plant species each year over the past 25 years. At that rate, they figure that researchers will add another 25,000 to the database by 2050.

“It is vital we have this information so that we know what each species is for conservation purposes,” Ulloa added.

The authors note that having a checklist like this one to serve as a baseline is helpful to scientists and policymakers alike — an assertion that Thomas Givnish, a botanist at the University of Wisconsin, who was not an author of this paper, highlights in another article published in the same issue of Science.

He calls the checklist “a monumental achievement that will be of enormous interest to conservation biologists, ecologists, evolutionary biologists, biogeographers, land managers, and governmental officials around the world.”


Ulloa Ulloa, C., Acevedo-Rodríguez, P., Beck, S., Belgrano, M. J., Bernal, R., Berry, P. E., … Jørgensen, P. M. (2017). An integrated assessment of the vascular plant species of the Americas. Science, 358(6370), 1614 LP-1617. Retrieved from

Banner image of Ponthieva mandonii by Fernando Zuloaga/Institute of Genomics and Integrative Biology.