Lyme Grass
Leymus arenarius
Tap image to enlarge · Wikimedia Commons
Overview
Lyme Grass is one of the most striking plants on the Sefton Coast — large, blue-green clumps of broad, stiff, strongly ribbed leaves on the fore-dune and beach edge. The blue-grey colour is distinctive and gives it an almost ornamental appearance in natural conditions. Like Marram Grass, it helps bind sand and stabilises the fore-dune, but it's typically found slightly further seaward and in less hostile positions than Marram. The tall flower heads appear in July and August.
At a Glance
| Order | Poales |
| Family | Poaceae |
| Habitat | Fore-dune · Upper beach · Mobile dune |
| UK population | Common on northern and eastern UK coasts; less abundant in the south |
| Sefton Coast | Common on fore-dunes and beach edges throughout the Sefton Coast |
| Conservation | UK Green List |
Where to See It
Fore-dune and upper beach edges throughout the Sefton Coast. Forms large, distinctive clumps.
Identification
Large clump-forming grass. Broad, stiff, strongly ribbed leaves. Distinctive blue-grey-green colour — unlike any other grass. Grows at fore-dune and beach edge. Tall straw-coloured flower spikes in summer.
Viewing & Photography Tips
The blue-grey colour makes it distinctive even from a distance. Look at the upper beach edge at Formby and Ainsdale.
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 Lyme Grass blue-green?
The distinctive blue-grey-green colour of Lyme Grass comes from a waxy surface coating on the leaves (cuticle) that reduces water loss and reflects some UV radiation. This adaptation helps it survive the extreme conditions of the fore-dune and upper beach — salt spray, drought, and wind exposure. The colour also reduces heating of the leaf surface in intense sunshine.
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.