Vivid displays of pink flowers on the southern cliffs are signs of yet another botanic invader from Southern Africa.
The plants, a species of Lampranthus, also known as dew plants, are particularly noticeable near Le Gouffre.
They are the same plants often seen in garden walls and now increasingly in hedgerows.
Guernsey Conservation Volunteers operations director Angela Salmon said the flowers were closely related to sour fig, the plant the group has painstakingly removed from much of the west coast.
‘They are from the same family and same region as sour fig,’ she said.
‘Environmentally they have the same impact, they will smother local species of plants and decrease our biodiversity. Some insects can feed on their flowers but are more likely to choose native plants if they can.
‘It’s a similar habitat here to Southern Africa in many ways, and here nothing eats them to keep them in check. Guernsey doesn’t have any baboons or wild tortoises.’
Like sour fig, dew plants were first brought here as garden plants. They were first recorded growing wild in 1961.
And the recent success of these plants in the island could be linked to global warming.
‘They really don’t like the cold, and without any significant frost in recent years, they have continued to spread,’ said Ms Salmon.
But unlike sour fig, the GCV has no plans to attempt to remove them, except at one special location – Pulias pond, near the Ronez quarry at Les Vardes.
‘This is a really special habitat,’ she said.
‘It’s a brackish pond with really specialist parts. We have removed lots over the last couple of years and have a work party due to go back in August to check it has not returned.’
However, if people want dew plants in their gardens or hedges, that was their personal choice, she said. The position of the flowers on the cliffs makes them too inaccessible for removal.
La Societe Botany section secretary Helen Litchfield described dew plants as a ‘big nuisance’.
‘We would eliminate them if we could. It’s controversial as they are so “pretty”,’ she said, ‘but like the sour fig, they smother local plants and are of little benefit to wildlife.
‘Lampranthus are grown in gardens all over the island, and you will frequently see them on old walls, deliberately planted as they will tolerate a high degree of drought or neglect,’ she said.
‘They are frost tender, so a frost will knock them back or out altogether. However, we have not had a proper frost for some years, so they are thriving.’
She added that the flowers on the southern cliffs and in hedgerows were often misidentified as Mesembryanthemums, or ice plants, another popular garden plant, and another member of the same family as sour fig and dew plants.
‘Mesembryanthemums have not been recorded growing in the wild in Guernsey and it’s important to make that distinction,’ she said.
All three types of plants are members of the Aizoaceae or fig-marigold family, and are often referred to as ‘carpet weeds’.
And while many are impressed by their vivid colourful display, Ms Salmon was slightly less enamoured.
‘Personally I find them a bit gaudy,’ she said.
‘But I’m probably programmed not to like them.
‘In the end plants are really here for the wildlife.’
You need to be logged in to comment. If you had an account on our previous site, you can migrate your old account and comment profile to this site by visiting this page and entering the email address for your old account. We'll then send you an email with a link to follow to complete the process.