An international research team has assembled the first complete list of all known vascular plant species in the Americas. The searchable database contains nearly 125,000 species representing one-third of all known vascular plants worldwide.

Vascular plants are land plants with specialized internal-transport and vertical-support tissues. The vast majority of plant species on Earth are vascular plants, including trees, shrubs, grasses, flowering plants and ferns.

In a project led by the Missouri Botanical Garden, 12 regional and national plant lists were merged into a single super-list for the Western Hemisphere. Twenty-four authors, including two from the University of Michigan, contributed to a paper published Dec. 22 in the journal Science.

"This is the first time we have a complete overview of the plants of the Americas," said lead author Carmen Ulloa Ulloa of the Missouri Botanical Garden. "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."

The new study is "a monumental achievement that will be of enormous interest to conservation biologists, ecologists, evolutionary biologists, biogeographers, land managers, and government officials around the world," University of Wisconsin botanist Thomas Givnish, who was not part of the study, wrote in a Perspectives article that accompanies the Science paper by Ulloa Ulloa et al.

The U-M authors are Paul Berry, a professor in the Department of Ecology and Evolutionary Biology and curator of vascular plants at the U-M Herbarium, and Lois Brako, U-M's assistant vice president for research – regulatory and compliance oversight.

Berry worked on several South American flora projects, published over the past two decades that were used in the new compilation. Brako was the main author of a list of Peruvian plants published in 1993 and was a postdoctoral researcher at the Missouri Botanical Garden at the time.

"This is the first time we've been able to merge all of this data into a central database—and do a fair amount of data cleanup and verification in the process—to yield an overall picture of all the different native vascular plants found in the Western Hemisphere, based on verified records covering the entirety of the region," Berry said.

Read full news release

Read more in Science Perspectives