Gentiana is a genus of flowering plants belonging to the gentian family (Gentianaceae), the tribe Gentianeae, and the monophyletic subtribe Gentianinae. With over 300 species, it is considered a large genus. Gentians are notable for their mostly large trumpet-shaped flowers, which are often of an intense blue hue.
The Habitats Directive is a directive adopted by the European Community in 1992 as a response to the Berne Convention. The European Community was reformed as the European Union the following year, but the directive is still recognised.
The flora of the U.S. Sierra Nevada alpine zone is characterized by small, low growing, cushion and mat forming plants that can survive the harsh conditions in the high-altitude alpine zone above the timber line. These flora often occur in alpine fell-fields. The Sierra Nevada alpine zone lacks a dominant plant species that characterizes it, so may or may not be called a vegetation type. But it is found above the subalpine forest, which is the highest in a succession of recognized vegetation types at increasing elevations.