From the University of Michigan:
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.
The new study includes a 2,600-page online plant checklist and a continuously updated, publicly searchable database on a Missouri Botanical Garden website.
The Missouri Botanical Garden’s plant database, Tropicos, was used as the project’s data repository. Tropicos is the world’s largest botanical database and is accessed more than 70 million times annually by researchers worldwide.
The plant checklist includes 124,993 native vascular plant species, which corresponds to one-third of the estimated 383,671 vascular plant species known worldwide. The members of this flora—which includes flowering plants, gymnosperms, ferns, horsetails, clubmosses and spikemosses—are categorized into 6,227 genera and 355 families.
The study shows that most of the Western Hemisphere’s plant diversity is in South America. Brazil has the most diverse flora, with 33,161 species, followed by Colombia (23,104) and Mexico (22,969).
The most diverse plant family in the Americas is Orchidaceae, the orchid family, with 12,983 species. It is followed by Asteraceae (12,043 species), a family that includes everything from garden ornamentals such as daisies, marigolds and zinnias to economically important food crops such as artichokes, lettuce and sunflowers.
The Missouri Botanical Garden is now working with more than 40 other institutions on a larger project known as the World Flora Online. The goal is to fully document all known plant life by 2020.
Direct to Vascular Plants of the Americas
Direct to World Flora Online