Marram grass spines. Light micrograph of a section through part of a leaf of marram grass, IAmmophila Iarenaria, ishowing surface spines. Marram grass is one of the commonest grasses to stabilise sand dunes. The leaf is rolled into a vertical tube and part of the folded inner surface is shown here. The folds conserve water and withstand salt to prevent excessive evaporation. Spine-like hairs on the surface (pink, pointed) discourage animals from eating the leaf. Inside the leaf, the blue regions are photosynthetic tissue and the colourless large-celled tissue is sclerenchyma. Magnification: x400 at 35mm size.