Ammophila arenaria leaf. Light micrograph (LM) of a section through a marram grass (Ammophila arenaria) leaf, showing the characteristics that help reduce water loss. The outer epidermis (outer circle) consists of a layer of thick cuticle and layers of thick walled sclerenchyma while the inner epidermis is folded and hairy to trap water vapour. Vascular bundles composed of phloem and xylem vessels can also be seen. Magnification: x25 when printed 10 centimetres wide.