An evergreen group of plants that are native to Northern and Central America. These extremely hardy plants are adaptable to most soils and positions and are drought resistant. Some species can attain a height of 4 m (Joshua Tree) but most are around 1.5–2 m. They provide a variety of leaf shapes and colours ranging form dark green to grey. The spectacular bell-shaped flowers are predominately white and are borne on erect terminal spikes. This Genus has become an increasingly popular landscape plant in the drought affected areas of Australia.