Humid gorse-heaths are dominated by cross-leaved heather (Erica tetralix), dwarf gorse (Ulex minor), with or without associated heather (Erica ciliaris), ling (Calluna vulgaris) and species of Genista also being present (habitat 4020).
This habitat has importance in controlling the cycle of water as well as providing a haven for biodiversity (rare vascular plants such as Gentiana pneumonanthe and rare butterflies, e.g. Maculinea alcon). Also insectivore species such as the round-leaved sundew (Drosera rotundifolia) can be found, along with pale butterwort (Pinguicula lusitanica). Humid scrub areas are extremely important faunal habitats notably for various bird and amphibian species such as Iberian newt (Triturus boscai), marbled newt (Triturus marmoratus), Iberian frog (Rana iberica) and tree frog (Hyla arborea).