Treasure trove of nearly 300 new plants discovered by Kew experts

Coffee plants, yams and orchids among bumper crop of species new to science

A massive tree that is a relative of the pea yet rises more than 135ft above the ground is among a treasure trove of plants and fungi discovered by botanists.

It is one of a "bumper crop" of almost 300 new species discovered in the past 12 months by scientists at the Royal Botanic Gardens in Kew.

They include colourful blooms such as orchids and passion flowers, giant trees, a yam reputed to cure cancer and a range of plants that have the potential to be cultivated as valuable crops.

The tally by Kew botanists this year accounts for more than one in seven of all new plants and fungi recorded around the world.

"We are turning out stuff all the time," said Dr Aaron Davis, a coffee plant specialist. "And there are all sorts of groovy things this year. Looking back on this year it's not just the number we've found that is special but the type of species we've found. It has surprised us. We have big canopy plants, numerous coffees, numerous palms and yams, and many orchids and indigos.

"The public perception is, 'Surely you know all the palms and coffee and big canopy plants by now?' But obviously we don't."

Most finds have been made in tropical areas of the world where many more types of plant and fungus grow than in cooler regions.

Seven new varieties of coffee plant, most of them in Madagascar, were among the discoveries and could offer growers alternatives to the crops they grow today.

Dr Davis said that the pleasure in discovering a new species remains undimmed even to someone who has uncovered scores: "I must have described over 200 species over the years and it's always exciting, particularly if it's something very, very different and it doesn't look like anything else you have ever seen. It's really exciting."

He added: "Most of our new finds are coming from the tropics because the areas have a higher density of plants than anywhere else. And some of these areas are almost totally unexplored.

"You would think that we know all the species of something like coffee which is a massively important crop but we've discovered nearly 30 in the last 10 years. And when you consider there are only 100 species in total that's pretty amazing.

"Coffee is the world's second most traded commodity, after oil, with at least 25 million farming families dependent on its production for their livelihoods, yet we still have much to learn about its wild relatives.

"Conserving the genetic diversity within this genus has implications for the sustainability of our daily cup, particularly as coffee plantations are highly susceptible to climate change."

The biggest new species to be discovered in 2009 by Kew botanists was the tree Berlinia korupensis, which is related to a pea. It boasts pods that grow a foot long and explode when ripe to hurl the seeds across the forest floor far from the parent tree.

It was found in the Korup National Park in Cameroon, but only 17 specimens were pinpointed, making it critically endangered.

Two other big trees, Talbotiella velutina and Lecomtedoxa plumosa, were also discovered in the Cameroon rainforests. Both grow to 100ft tall.

In South Africa botanists discovered the "cancer cure" yam, Dioscorea strydomiana, which is held by locals to have healing properties. Despite being known locally it had escaped identification by scientists.

Only 200 of the plants have been pinpointed, and Dr Paul Wilkin, Kew's yam expert, said: "This is the most unique and unusual yam I have come across, and probably the most threatened."

An unexpectedly small plant was a knee-high dwarf eucalyptus in Australia named Eucalyptus sweedmaniana which, along with a second, Eucalyptus brandiana, was discovered by Professor Stephen Hopper, Kew's director. He said: "It is not widely known that 2,000 new plant species are discovered worldwide each year. Kew's botanists make a very significant contribution to this total.

"These new discoveries highlight the fact that there is so much of the plant world yet to be discovered and documented. Without knowing what's out there and where it occurs, we have no scientific basis for effective conservation."

The number of new species was counted and announced as part of Kew's 250th anniversary celebrations. Scientists exceeded their hopes of making 250 discoveries – one for each year.

The country where the most new species were discovered by Kew experts in 2009 was Tanzania with 67, followed by Borneo with 62 and Madagascar with 32.

The smallest of the new species discovered by Kew this year was a fungus in Australia that rots wood but is less than a millimetre thick. "They are small but they perform a vital role in decomposition of plant material and recycling of nutrients," said Dr Brian Spooner.

Researchers found 38 new species of orchids, of which 13 came from Mount Kinabalu, Borneo's highest mountain. A further 15 were found in other parts of Borneo, where they are threatened by logging and plant hunters. Another new bloom is a type of passion flower from Brazil, Passiflora cristalina, which is bright red with an egg-shaped fruit.

The biggest of 24 new species of palms was Cyrtostachys bakeri, from Papua New Guinea, which reached more than 80ft high. The majority of new palms, 20 of them, were found in Madagascar, where they are threatened because 200,000 to 300,000 hectares of forest are destroyed annually.

Other discoveries with commercial potential include 14 species of indigos and their relatives, a type of plant that has been used for dyes for centuries.

Unearthed: 10 species found by Kew scientists

*Wood-rotting fungus Less than a millimetre thick, the fungus helps with decomposition of plant material.

*Gymnosiphon Less than 10cm tall, these plants derive their energy from underground fungi.

*Dioscorea strydomiana A critically endangered yam species which is shrub-like in appearance with a slow-growing, lumpy tuber. *Passiflora cristalina

A red passion flower comprising edible egg-shaped fruits. It is pollinated by hummingbirds and is under threat from deforestation.

*Coffea boinensis One of seven new coffee species, it contains one of the largest coffee beans.

*Isoetes eludens A plant from a group of spore plants known as quillworts. The rock pools in which they are found are vulnerable to climate change, say botanists.

*Eucalyptus sweedmaniana An Australian-based plant can survive bush fires by dying back to a woody underground rootstock.

*Berlinia korupensis An enormous tree that can reach 42m into the canopy. Extremely rare with only 17 trees found in the wild.

*Eucalyptus brandiana One of over 900 species of eucalypts that are integral to the landscape and culture.

*Tabaroa catingicola Legumes found in the Rio de Contas mountain range in south-western Bahia. Used in food and medicine.