The sedge was found on the west coast of Scotland
The UK public is being called upon to help hunt for a rare grass-like plant.
Botanists recently discovered a species of sedge growing on the west coast of Scotland that had never before been seen in Britain.
Saltmarsh sedge, or Carex salina, is found along the coast of Scandinavia, northern Russia and the eastern seaboard of North America.
The team plans to enlist extra help to establish if other populations exist or if this really is a new UK inhabitant.
The saltmarsh sedge was discovered in 2004 at Morvich, at the head of Loch Duich, and was sent to Edge Hill University in Lancashire for analysis.
The hunt is now on for more saltmarsh sedge populations
"We knew this was something different; not something we have in the UK," explained Dr Paul Ashton, a botanist at the university.
Further investigation revealed the plant was C. salina, and a paper describing the find is to be submitted to the Botanical Society of the British Isles' journal.
"Normally we worry about plants becoming extinct - that's the general trend, we lose species in this country," Dr Ashton told the BBC News website.
"So to find something completely new is extremely unusual and really, really exciting."
Sedges are one of the largest plant families in the world and are most common in wet habitats.
They can be distinguished from grasses by their triangular rather than cylindrical stems.
C. salina joins 106 species of sedge common to the UK, including saw sedge (Cladium mariscus) which is used by the thatching industry.
One of the largest plant families in the world, with 5,000 species
Found all over the world
Most common in wet conditions
About 106 species exist in Britain
Papyrus is a species of sedge
Saw sedge is used in the thatching industry
The researchers believe there are several possibilities for this plant's appearance.
It could have arrived by long-distance dispersal, through roots or seeds being carried by sea, bird or boat to Scotland, explained Dr Ashton.
Another option is it may be native to the UK.
Saltmarsh sedge is the result of hybridisation between two other sedge species - but neither of these are found in the UK botanical record.
However, the parent species may have existed here once, generating C. salina before themselves going extinct. It is also possible the parent plants are still present and breeding but they are undetected.
The research team is now calling on the public to help it look for examples of this sedge to discover if the plant is a long-term UK resident or a new visitor.
"We are really keen to enlist the help of others in looking for this species," said Dr Ashton, who is encouraging botanist enthusiasts to visit the research website to find out how they might help.
"It is entirely possible that this plant has been on our shores for many years and just overlooked, but we will never know that unless people help us with our study.
"If we find that saltmarsh sedge is entirely new to the UK then that will be a very exciting find."