The closed orchid-rich phase of dune slack succession is probably the most colourful and aesthetically pleasing of all dune habitats. In contrast to the successionally-young seral stage, there is no obvious bare sand visible, and the vegetation is dominated by a mix of medium to tall herbs and grasses, typically with an abundance of orchids, notably early marsh orchid (Dactylorhiza incarnata), southern marsh orchid (Dactylorhizza pratermissa), marsh helleborine (Epipactis palustris) and Fragrant orchid (Gymnadenia conopsea).
