Experts at Kew Gardens have named a newly discovered tropical tree after the actor and environmentalist Leonardo DiCaprio.

The Uvariopsis dicaprio, which grows to 4m (13ft) tall, is from the ylang-ylang family with large yellow-green flowers on its trunk.

It was discovered in the Ebo Forest in Cameroon and is the first new named plant species of 2022.

It is one of the top 10 highlights named by scientists at the Royal Botanic Gardens from more than 200 plants and fungi officially named new to science.

These range from a killer tobacco plant to a ghost orchid that grows in complete darkness.

The tree named after the Oscar-winning actor and activist was collected by Kew scientist Lorna MacKinnon.

The star was chosen for the honour after taking part in a social media effort, alongside conservation organisation Re:wild, to get a logging concession in the Ebo Forest revoked in February 2020.

Ebo Forest is one of the largest intact rainforests in Cameroon, ancestral home to the Banen people, threatened gorillas, and the world's only chimps known to both crack nuts and fish for termites, as well as forest elephants and 75 threatened species of plant.

The cancellation of the concession by the president of Cameroon in August 2020 raised hopes that the wildlife found there can avoid extinction.

Dr Martin Cheek, senior researcher in RBG Kew's Africa team, said: "We very much appreciated the support Leo gave us in campaigning to protect Ebo last year so it seemed fitting to honour him in this way, naming a species unique only to this forest, after him.

"Had the logging concession gone ahead, we would have likely lost this species to timber extraction and slash-and-burn agriculture that usually follows logging concessions."

Sadly, Uvariopsis dicaprio continues to be assessed as critically endangered. This is because the forest where it was found is unprotected, and the threat of logging, mining and the conversion of land to plantations continues.

Scientists at RBG Kew and their partners around the world, who study unknown species, assemble the data to provide evidence they are new to science, decide on names and publish them in scientific journals, named 205 plants and fungi from Africa, Asia, the Americas and even the UK in 2021.

Dr Cheek said many species - particularly in the tropics - remain without scientific names, making assessment of their extinction risk "near impossible" and protection incredibly difficult.

"Sadly, several species in 2021's list are already considered as under threat of extinction from increasing threats to their natural habitat, and three are already believed to be extinct in the wild.

"This list is another reminder that this is our last chance to find unknown species, name them and hopefully protect them before they become globally extinct," he said.

Highlights include:

• Nicotiana insecticida: a tobacco plant that snares and kills small insects on stick glands, which was collected beside a truck stop on Northwest Coastal Highway in Western Australia and cultivated at Kew Gardens where it continues to kill insects.

• Hydnellum nemorosum: a rare tooth fungus from the UK which was found growing in moss under a sweet chestnut in Windsor Great Park in 2008, the only known site it is found in Britain, and which was finally described as new to science in 2021.

• Some 14 species of bright-blue-fruited rainforest shrubs in the coffee family were named in 2021, including Chassalia northiana, named after Victorian female explorer and artist Marianne North, who painted the Bornean species in 1876, in a picture which hangs in her gallery in Kew Gardens today.

• Fusarium chuoi: a new species of microscopic fungus found growing within the seed of a wild banana from Vietnam at Kew's Millennium Seed Bank, in Wakehurst, West Sussex.

• Some 16 new species of orchids from Madagascar were named, including a "ghost orchid" - Didymoplexis stella-silvae - with star-like white flowers which grows in complete darkness and depends on fungi for its energy.

• Barleria thunbergiiflora: a beautiful blue Barleria was uncovered on a National Geographic expedition to Angola, where it only grows at three sites in high elevation grasslands on Kalahari sands.

• Five new species of Cape primroses were named as new to science from the Democratic Republic of Congo, including Streptocarpus malachiticola, found in the mining region of Katanga growing on malachite, a copper ore which is in high demand, making the species endangered.

• Ardisia pyrotechnica: a member of the primrose family named for its resemblance to an exploding firework when flowering, which grows up to 4m (13ft) tall and was found in the forest of Borneo where it is critically endangered due to the threat of palm oil plantations.

• Philibertia woodii: a yellow-flowered periwinkle from the Andean valleys in Bolivia, which has egg-shaped kiwi-like fruits that are edible when roasted, flowers that attract butterflies, and the potential for medicinal value.

• Pseudohydrosme ebo, a pink voodoo lily, which flowers from an underground tuber when the leaves have died down, with a flower spike that can reach 30cm (1ft). It is restricted to a small corner of the Ebo Forest of Cameroon.