How many different plants are there in the world?

10 May 2016

A new mammoth report into all known species of plants on the planet has found that just shy of 400,000 are known, however, a growing number are at risk of, or have become, extinct.

A new report on plants worldwide has found that there are roughly 390,900 species known to science, in a first-ever global tally. Put together by the Royal Botanic Gardens (Kew), the report lists the total number of new species found each year, while also dealing with mass duplicates, discoveries made from stored examples and the growing risk of extinction throughout the globe.

How many plants are there in the world?

Presumed extinct

Future Human

For example, of the 2,034 species discovered last year, several are already presumed extinct. One is a 12–15m tall tree species of Ghana and the Ivory Coast, where its dry forest habitat has been reported as cleared for agriculture or destroyed by fires.

Another “waterfall-specific” family – and the smallest flowering species discovered last year – is the Ledermaniella lunda.

Its only known location is now the site of a hydroelectric dam, “and diamond-mining has turned the river waters brown and turbid, a death-sentence for plants of this family”, reads the report.

However, beyond the growing threats, this documenting of such a wide array of plant species seems a remarkable achievement, although it’s surprising that no such achievement was made before.

Snowdrop anemone in the forest, via Shutterstock | How many plants are there in the world?

Snowdrop anemone in the forest, via Shutterstock

A milestone

“The State of the World’s Plant Report is a significant and necessary milestone, not only for Kew but for the science community as a whole,” said Prof Kathy Willis, director of Kew.

“We are facing some devastating realities if we do not take stock and re-examine our priorities and efforts in answering the bigger questions we face today, from global food security to mitigating the worst impacts of climate change.

“This report will be a baseline for all on the important indicators that tell us how we are faring and show us the direction we as a global community can go, if we so choose.”

Licorice roots on the way to in Italy, via Shutterstock | How many plants are there in the world?

Licorice roots in Italy, via Shutterstock

Many uses

The report is fantastic, listing not just species and geographical locations, but also things like plants’ resultant industry, value and medicinal products.

For example, 5,538 plant species are consumed by humans as food, while three times that go towards medicine. 2,503 are used in poisons, with half that used by humans for ‘social’ reasons –  these include plants used as intoxicants or for religious reasons.

Of the 390,900 known species, 369,400 are flowering, with Willis claiming we’re just ‘scratching the surface’. “There are thousands out there that we don’t know about,” she said.

Of the 2015 discoveries, there’s the Canavalia reflexiflora, which is a hummingbird-pollinated papilionoid legume, related to the Jackbean. There’s also the carnivorous Drosera magnifica, a 1.5m tall insect-eater found in Brazil. It’s one of the largest three sundews known to science.

The new-found Drosera magnifica, via Wikimedia Commons | How many plants are there in the world?

The new-found Drosera magnifica, via Paulo Gonella/CC BY-SA 3.0/Wikimedia Commons

Main image of rhododendron flowers in the Carpathian Mountains via Shutterstock

Gordon Hunt was a journalist with Silicon Republic