Plants are everywhere, but how much do we really know about them?

A report from the Royal Botanic Gardens at Kew, calling itself the first document to collate current knowledge on the state of the world's plants, is laying out a baseline for the massive undertaking of doing inventory on planet Earth's plant collection.

Just how many vascular plant species are known to science? How many new species are there? How many are being lost forever? How is climate change affecting them?

The plan is for the study - "State of the World's Plants" - to be updated and added to each year, appropriately a kind of organic, growing data base.

"We cannot claim to have covered all of the evidence currently available," the report's author Professor Kathy J. Willis, science director at Kew gardens, writes. "We hope to raise the profile of plants among the global community and highlight not only what we do know about threats, status and uses, but also what we don't."

"The positive is we're still discovering lots of new plants, about 2,000 each year, new plants for food, for fuel, for drugs," Willis said. "On the negative, we've seen a huge change in land cover, mainly driven by cultural activity, with a little bit of climate change in there as well."

More than 80 top scientists contributed to the document and their findings suggest this project could turn into a mushrooming affair.

With an estimated 391,000 vascular plant species known to science, an average of 2,000 new ones are discovered and named each year.

China, Brazil and Australia have been the top three source countries for the identification of new plants for the last 10 years, with China logging in about 150 new species annually.

Among the new finds for 2015 was a carnivore - the insect-eating Drosera magnifica which grows to five-feet tall. Seems hard to miss, but it's in Brazil.

And gastronomes will be pleased to learn that 13 new members of the onion, garlic, scallion, shallot, leek and chives family were discovered, including five new cultivatable onions.

The report also finds that 21 percent of species are threatened with extinction, mainly because habitat is being cleared for human use.

An estimate 369,000 species of flowering plants are documented by modern science; 31,128 plant types are used for medicine (17,810 species in the pursuit of good health), human and animal food, fuel and things like textiles and construction materials.

It is too early to accurately judge the impact of climate change, Willis told The Associated Press, but the report finds most of the world's ecosystems have experienced a greater than 10 percent change in land-cover in the last 10 years, due to changes in land use and climate change.

Yet, "less than 10 percent of the Earth's vegetated surface demonstrates high sensitivity to climatic variability," the report said.

The arcane method of discovering, describing and naming a new species may seem of only academic value, but Timothy M.A. Utteridge, head of identification and naming at the Royal Botanical Gardens, explained that the information is vital if modern science is to protect plants.

Last year alone he helped name 12 new species and sees a remarkable number of new plants tagged in Australia, Brazil and China, all of which are developing new databases with comprehensive details about their plants.

That's step one in protecting those plants, he said.

"If this plant doesn't have a name, and it falls over in the forest, no one knows," he said. "Once we have a specimen, and a name, we put that on the map," he said, adding that it's important for "conservation assessment."

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