Araucaria are mainly large trees with a massive erect stem, reaching a height of 5–80 metres (16–262 ft). The horizontal, spreading branches grow in whorls and are covered with leathery or needle-like leaves. In some species, the leaves are narrow, awl-shaped and lanceolate, barely overlapping each other; in others they are broad and flat, and overlap broadly.
The trees are mostly dioecious, with male and female cones found on separate trees, though occasional individuals are monoecious or change sex with time. The female cones, usually high on the top of the tree, are globose, and vary in size among species from 7 to 25 centimetres (2.8 to 9.8 in) diameter. They contain 80–200 large edible seeds, similar to pine nuts, though larger. The male cones are smaller, 4–10 cm (1.6–3.9 in) long, and narrow to broad cylindrical, 1.5–5.0 cm (0.6–2.0 in) broad.
The genus is familiar to many people as the genus of the distinctive Chilean pine or monkey-puzzle tree (Araucaria araucana). The genus is named after the Spanish exonym Araucano (“from Arauco“) applied to the Mapuches of central Chile and south-west Argentina, whose territory incorporates natural stands of this genus. The Mapuche people call it pehuén, and consider it sacred. Some Mapuches living in the Andes name themselves Pehuenches(“people of the pehuén“) as they traditionally harvested the seeds extensively for food.
No distinct vernacular name exists for the genus. Many are called “pine”, although they are only distantly related to true pines, in the genus Pinus.