A new species of wild flower has been discovered on a Scottish island.

Scientists have found a special type of yellow monkeyflower growing in Shetland and say that its evolution has happened in the last two centuries.

It is the descendant of a non-native species, the yellow monkeyflower (Mimulas guttatus), which was colonised in the United Kingdom during Victorian Times.

The new plant is referred to by researchers at the University of Stirling as ‘Shetland’s monkeyflower’ and produces yellow flowers with small red spots.

It is larger than the typical monkeyflower and its flowers are more open.

Researchers say the finding is significant as it shows that a major evolutionary step can occur in non-native species over a short period of time, rather than over thousands of years.

Associate Professor Dr Mario Vallejo-Marin, from the university, said: “Evolution is often thought to be a slow process taking thousands or millions of years.

“Yet we show that a major evolutionary step can occur in a couple hundred years.”

Researchers carried out tests after a “chance encounter” with the plant while conducting fieldwork near Quarff, Shetland.

They measured the plant’s genome size and surveyed 30 populations of monkeyflowers from Shetland and across the United Kingdom.

The plants were then grown under controlled conditions where their floral and vegetative states were measured to compare the effects of genome duplication in flowering time.

They also carried out genetic analysis to look at the relationship between the new polyploid plant and other flowers in the Shetland Isles.

A polyploid plant has more than double the basic number of chromosomes and crops such as potatoes, tobacco and coffee are polyploids.

Genome duplication is common in the evolutionary history of flowering plants but it is rare to witness such a phenomenon in recent years