This is the English version of a guide to the woody plants of the Majella National Park in Central Italy, created in collaboration with the european project KeyToNature as an answer to a recurring question from visitors: "How can we know the names of the myriad of plants we see when hiking, camping, or just observing nature in the Park?" The identification of plants is often a matter for experts, because most of the “professional” identification keys rely on the hierarchical scheme of biological classification. One has to start with a key to families, go on with a key to genera within a family, and finally proceed with a key to species within a genus. But the characters that distinguish families or genera are often "difficult" and many of them can be appreciated with a stereomicroscope. Our guide is based on easily observable characters, richly illustrated by pictures and/or drawings. It can be used also by persons which approach the identification of plants for the first time. This guide is "easy", but scientifically rigorous. It includes all species and subspecies of woody plants (trees, shrubs, and woody climbers), which occur in the wild, plus some of the most common alien plants used for reforestation. The Italian version has a taxon page for each species, reporting common names, synonyms, morphology, distribution, ecology and uses in the local tradition.