Marsh Pennywort
Hydrocotyle vulgaris
Tap image to enlarge · Wikimedia Commons
Overview
Marsh Pennywort forms carpets of round, penny-shaped leaves in the wet dune slacks at Ainsdale. The leaves are distinctive — perfectly round with a stalk attached at the centre, like a tiny parasol. It creeps through wet grass by underground runners. The flowers are tiny and largely hidden under the leaves. A characteristic and abundant plant of the wet slack community.
At a Glance
| Order | Apiales |
| Family | Araliaceae |
| Habitat | Wet dune slack · Bog · Fen grassland |
| UK population | Common in wet grassland and fen throughout Britain |
| Sefton Coast | Common in wet dune slack grassland throughout Ainsdale NNR |
| Conservation | UK Green List |
Where to See It
Wet dune slacks at Ainsdale NNR. Forms carpets of round leaves in permanently wet areas.
Identification
Creeping plant. Perfectly round, scallop-edged leaves with central stalk. Forms dense carpets in very wet grassland. Tiny pinkish flowers hidden under leaves. In wet, boggy dune slacks.
Viewing & Photography Tips
Walk any wet dune slack at Ainsdale — the carpets of round leaves are unmistakeable. Get low to see the structure of the individual leaves.
Conservation Status
UK Green List
This species has a favourable conservation status in the UK and remains an important part of Sefton Coast biodiversity.
Frequently Asked Questions
Why is the stalk of Marsh Pennywort attached to the centre of the leaf?
Marsh Pennywort is 'peltate' — the leaf stalk attaches at the centre of the leaf rather than the edge. This is relatively unusual in British plants and is thought to help water run off effectively in the wet, boggy habitats where the plant grows, preventing the leaf from becoming waterlogged and sinking. The perfectly round shape and central stalk are the key identification features.
Related Species
Plan your visit to the Sefton Coast
Marshside RSPB, Formby pinewoods, Ainsdale NNR — practical guides to getting there, what to bring, and the best spots for each season.