New species of wild flower discovered on Shetland

The new plant has been called "Shetlands monkeyflower".

Scientists have found a type of yellow monkeyflower growing in Shetland, which they say has evolved over the past 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, with more open flowers.

Researchers say the finding is significant as it shows that a significant 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 of Stirling, 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.

Researchers said young polyploids, such as the new plant, provide an opportunity to investigate the early stages of an important evolutionary process.

Dr Vallejo-Marin added: “This raises the possibility that non-native species may increasingly participate in major biological processes, including the formation of new  types of plants and animals.”