New Monkey Flower Species Discovered in Scotland, Originated Within Last 150 Years

Posted on July 10, 2012

A new species of monkey flower - created by the union of two foreign plant species - has been discovered on the bank of a stream in Scotland. Genetic changes have allowed the yellow-flowered hybrid to overcome infertility. It is a rare example of a brand new species that has originated in the wild in the last 150 years.

The ancestors of the new plant were brought from the Americas in the 1800s and were quickly adopted by Victorian gardeners. Soon after their arrival, they escaped the confines of British gardens. They can be found growing in the wild, along the banks of rivers and streams. Reproduction between these species produces hybrids that are now widespread in Britain. Genetic differences between the two parents mean that the hybrids are infertile and cannot go beyond the first generation.

Dr Mario Vallejo-Marin, a plant evolutionary biologist at the University of Stirling, has documented the first examples of hybrid monkey flowers that have managed to overcome these genetic barriers and show fully restored fertility. This fertile hybrid derived from 'immigrant' parents represents a new species, native to Scotland. Dr Vallejo-Marin has chosen to name this species Mimulus peregrinus, which translates as 'the wanderer'. The species is described here in the open access journal PhytoKeys.

Dr. Vallejo-Marin says, "The two American monkey flowers are unable to produce fertile hybrids due to differences in the amount of DNA present in each species, the equivalent of getting a sterile mule from crossing a horse and a donkey. However, in rare cases, duplication of the entire hybrid DNA, known as polyploidization, can balance the amount of DNA and restore fertility. Our studies suggest that this is what has happened here."

PLANTS