If you want to discover a new species, try going for a walk. You might well spot something.
While around 1.2 million species of living organisms have been identified and described, there are probably far more waiting to be found. One recent study estimated there are another 6.8 million animals, 567,000 fungi and 90,000 plants awaiting discovery. New species are being found at a rate of 15,000 to 20,000 per year.
While most are found in remote environments like rainforests, caves and the ocean depths, other discoveries happen much closer to home. Here are five examples of new animals, plants and fungi found living under our noses.
The patch-nosed salamander is only known to science because of a mix-up. One day in 2007, postgraduate students Bill Peterman and Joe Milanovich misunderstood the directions they had been given to a study site.
They ended up 20 metres from a country road near Toccoa, Georgia. Peterman looked under some leaves near a stream, and found what looked like a baby salamander.
The tiny amphibian turned out to be a female carrying eggs, but they could not identify it. Even their supervisor Carlos Camp of Piedmont College, whose directions they had misinterpreted, was baffled when they showed it to him later that day.
It turned out that Peterman had found a lungless salamander so novel that it was not only a new species, but a whole new genus, or group of species. Its DNA and bone structure were both unusual.
It was the first new four-footed organism found in the US for 50 years.
Later they found that the salamander "was most likely one of the founding species that led to the diversification of this whole group of salamanders in the eastern US," says Milanovich, who is now at the Loyola University of Chicago in Illinois.
Bryn Dentinger discovered three new species of fungi in a packet of dried mushrooms bought in a London shop.
The Italian word "porcini" is used differently by different people, but it often refers to a group of 20-odd edible species related to Boletus edulis, the King Bolete or Penny Bun. But mushrooms imported from China and sold as porcini are generally from different species to those picked in Europe.
Last year, Dentinger's wife Rachel bought a 30g packet labelled as dried porcini originating from various countries from a small shop in Twickenham, London. Dentinger, of the Royal Botanic Gardens, Kew, in London, decided to investigate. DNA analysis of 15 randomly selected pieces revealed they belonged to three unknown Boletus species.
They had long been picked and eaten in China but scientists had thought they were the same species. Dentinger named them Boletus bainiugan, B. meiweiniuganjun and B. shiyong.
"Porcini is the fungal equivalent of an elephant in the animal kingdom," says Dentinger. "It's probably the mostly easily observed and widely recognised mushroom there is, and yet it can still end up in a shop in London and not have been correctly described by science."
Around 100,000 species of fungi are known, and a recent study estimates there are around 6 million out there.
You would not expect to find a new species of frog in New York City. But it has happened.
In 2008 Jeremy Feinberg, then a postgraduate student at Rutgers University in New Jersey, was studying southern leopard frogs on Staten Island when he heard a distinctive "single-note unpulsed chuck" noise. It stood out from the more repetitive sounds of other local frogs.
Feinberg realised the unusual calls were rarely heard in the same places as the familiar ones. He found that the frogs making them were similar to two known species, but had different hind leg markings. Genetic tests and acoustic analysis of the frog's calls showed that the Atlantic Coast leopard frog was a new species.
It was named Rana kauffeldi after Carl Kauffeld, a former director of Staten Island Zoo. In 1937 he suggested that there was an undiscovered frog in the region, but was dismissed.
One reason the amphibian remained hidden in a city of 8.4 million people is that it only makes its mating calls for a few weeks each year, and even then it's often drowned out by the spring peeper chorus frog.
However, others have now reported hearing its call at other wetlands along the US east coast, from Connecticut to North Carolina.
With a population of 134, the Texas town of Valentine may not have all the attractions of New York, but earlier this year it also gave up a new species. A single prickly plant found in the town turned out to be a new species called Solanum cordicitum, meaning "from the heart" in Latin.
It was actually the third known specimen. The first was found in 1974 near Fort David, Texas, and the second in 1990 in Valentine. Both were wrongly identified as known members of the Solanum genus, a large group of flowering plants that includes potatoes, tomatoes and aubergines.
Lynn Bohs of the University of Utah in Salt Lake City, suspected that was wrong. The plants had different coloured and sized flowers, different shaped leaves and different stalk lengths. In 2010 she found differences in DNA, but could not find another specimen.
Last November, Jeffrey Keeling of Sul Ross State University in Alpine, Texas, finally found the third specimen in Valentine. It was identified as a new species in July.
But Bohs is not satisfied. "He looked everywhere and finally found one horrible, wilted plant specimen," she said. "We were sad because we wanted a beautiful picture of the flowers." Bohs has asked anyone who spots another S. cordicitum to get in touch.
Until a few years ago, "zombie worms" were thought to only exist deep in the ocean. So scientists were astonished when they discovered a new one in just 120 m of water off the Swedish coast.
Osedax is a genus of worms related to earthworms and leeches. They live in and eat whale and fish bones. Females can grow to 2cm, with colourful feathery plumes that act as gills, and root-like structures that bury into and dissolve bones to get at the fats and proteins they use as nutrients. Males are much smaller, live attached to the females, and are basically sperm banks.
They were discovered in 2002, on the bones of a decaying grey whale in Monterey Bay, California, almost 3 km (2 miles) down.
But in 2004, marine biologists found zombie worms living in the remains of a dead minke whale they had sunk for research purposes in the relatively shallow waters of the North Sea.
The new worms were very similar to those found in Monterey Bay despite being so far away and at such a different depth. The following year they were officially named Osedax mucofloris: for those who don't speak Latin, the bone-eating snot-flower worm.