Scientists at the Royal Botanic Gardens in Kew made the discoveries during a series of expeditions to some of the remotest corners of the world.
Yet despite only recently being catalogued, many of the new plants could disappear all together due to threats to their habitats.
One tree, found growing on top of a ridge among knife-like limestone blades of rock in Thailand, oozes a dark red sap - rumoured in local folklore to be “dragons blood” and drunk as a medicinal tonic - is already considered threatened.
Dr Paul Wilkin, a team leader at the herbarium at Kew who identified the tree as a new species, said the limestone outcrops where it grows are quarried for building material while it is also heavily collected by locals who consider it to be lucky.
With tough leathery leaves and a dark red sap that oozes from the bark when damaged, it is known as the Red Dragon Tree, or Chan Daeng in Thai. The botanists have now given it the scientific name Dracaena jayniana. ....................................................................................................... Related ArticlesGiant tree and tropical mistletoe: 2010 finds 19 Dec 2010 Botanists launch bid to rescue the world's threatened habitats 20 May 2012 ....................................................................................................
Dr Wilkin said he found the tree after being led up a trecherous ridge of limestone near Chiang Mai by local scientists and believes he has found a second new species growing in similar locations.
He said: “The tops of these karsts are covered in weird vegetation. The limestone mountains are very steep sided and have knifelike ridges, so you can’t have any farming there, so you get these quite remarkable plants growing there.
“There is a real overlooked diversity of plants in Thailand. The Red Dragon Tree is related to other species that are also used for medicinal purposes. They are used for everything from curing wounds, fractures, piles and stomach ulcers.
“This one seems to be used as a general pick me up tonic, but what the exact medicinal function is will need some more research.”
Scientists at Kew also discovered a new snowdrop, which they namedGalanthus panjutinii, or Panjutin’s snowdrop after a famous climber and naturalist in the Caucasus Mountains called Platon Sergeevich Panjutin.
It was found on just one moutain ridge in Russia and joins 30 other species of snowdrop previously known in the world. The scientists, however, fear the new flower could already be under threat due to the small area it is found in.
They are refusing to reveal the exact location for fear that bulb hunters will raid the mountain side in search of the new species to sell to gardeners.
A new orchid, named Ornithocheirus cacharensis, was also discovered in the Cachar region of Assam, in northern India, a region better known for its tea. There are thought to be just ten of these red and purple plants in an area that measures less than three square miles.
Botanists also discovered 15 new species of palm tree. One example Indonesia, called Adonidia maturbongsii, has huge bat-like leaves while another from Papua New Guinea, called Heterospathe barfodii, produces clusters of purple flowers.
They also found 14 new species of Indigofera, a type of plant that was widely used to produce indigo dyes.
One expedition to the South Atlantic Island of St Helena, a UK Overseas Territory, discovered a new species of grass, which they namedEragrostis episocpulus, or wavy hair grass.
David Simpson, acting head keeper of the herbarium at Royal Botanic Gardens, Kew, said: “St Helena is a small island, so you might have thought that almost everything should have been found there, but the fact this has only just been discovered makes it more interesting.
“A lot of species on that island are not found anywhere else in the world and that makes them very special.”
Many of the new species discovered by Kew’s scientists, however, are already under threat.
The scientists also discovered some new species had already been collected in the past but had been misidentified before being locked in drawers in Kew’s vast herbarium.
They found 11 new species of Orania, a type of palm tree, hidden in the archives.
Dr Simpson added: “Techniques like DNA sequencing is helping us to work out relationships with other plants and it is a tool we have not had available in the past.
“In general we think there are something like 70,000 news species still out there waiting to be discovered.
"You often find these things more by chance than by anything else – if you happen to be in the right habitat when a particular plant is flowering.