Araucaria is a genus of large, ancient evergreen conifers in the family Araucariaceae, comprising around 20 extant species. Trees typically grow 5–80 metres tall, with massive erect trunks and horizontal branches arranged in regular whorls, giving many species a striking, architectural silhouette. Leaves range from broad and leathery in the South American species to narrow, awl-like needles in the New Caledonian members. Most South American species are dioecious, while the remainder are monoecious. Female cones are large and globose—7–25 cm across—and contain 80–200 edible seeds. Male cones are 4–10 cm long.
The genus is classified into four sections. Section Araucaria (South America) includes species with broad leaves and large cones. Section Bunya contains only A. bidwillii of Queensland, Australia. Section Intermedia contains only A. hunsteinii of New Guinea. Section Eutacta encompasses 14 species, all endemic to New Caledonia, which harbour the highest diversity in the genus and are thought to have undergone recent adaptive radiation on ultramafic, nickel-rich serpentine soils.
Araucaria is a genus of ancient lineage: fossil evidence places the group in the Jurassic period, when it had near-global distribution. Today its wild range is almost entirely restricted to the Southern Hemisphere — the mountains of Chile and Argentina, subtropical forests of southern Brazil, the forests of eastern Australia and New Guinea, and the islands of New Caledonia and Norfolk Island. Living populations are largely relicts with restricted ranges, favouring exposed sites in forests and maquis shrubland.
The genus has substantial cultural and economic importance. Seeds of several species — particularly A. araucana, A. angustifolia, and A. bidwillii — are a traditional food source for the Mapuche of Chile and Argentina, the Kaingang of southern Brazil, and Indigenous Australians. The Mapuche name for A. araucana is "pewen," and the species holds deep spiritual significance in their culture. Several species also provide commercially important timber, and multiple members are widely cultivated as ornamental trees for their bold, symmetrical form.
Etymology
The genus name Araucaria derives from the Spanish exonym "Araucano," applied to the Mapuche people of south-central Chile and southwest Argentina. The Mapuche ancestral territory — called Araucanía — contains the largest natural stands of A. araucana, the type species. In the Mapuche language, A. araucana is known as "pewen," and the tree is considered sacred; communities who hold it central to their culture are called Pehuenche ("people of the pewen").
Taxonomy
Araucaria Juss. was formally described by Antoine Laurent de Jussieu in 1789 in Genera Plantarum: 413. It belongs to the family Araucariaceae within the order Pinales, class Pinopsida. GBIF (usageKey 2684910) records 83 descendant taxa including synonyms. The genus is divided into four sections:
- Section Araucaria: South American species with broad leaves and large cones (>12 cm); includes A. angustifolia and A. araucana.- Section Bunya: A single living species, A. bidwillii, with recalcitrant (non-storable) seeds.- Section Intermedia: A single living species, A. hunsteinii of New Guinea, also with recalcitrant seeds.- Section Eutacta: Fourteen species endemic to New Caledonia with narrow, awl-like leaves and smaller cones (<12 cm).
Molecular phylogenetic studies recover two major clades: one uniting sections Araucaria, Bunya, and Intermedia; the other a monophyletic section Eutacta. The synonym A. excelsa is used in older literature for A. heterophylla.
Distribution
Wild Araucaria populations are concentrated in the Southern Hemisphere. South American species (A. araucana, A. angustifolia) occur in Chile, Argentina, southern Brazil, Paraguay, and Uruguay, mainly in montane and subtropical forests at 600–2,300 m. Australian members (A. bidwillii, A. cunninghamii) occupy eastern Australia's subtropical and tropical forests. A. hunsteinii is native to New Guinea. A. heterophylla is endemic to Norfolk Island. New Caledonia hosts the greatest diversity with 14 endemic species in section Eutacta, most adapted to ultramafic soils.
Fossil evidence shows the genus had near-global distribution during the Jurassic and Cretaceous; it extended well into the Northern Hemisphere until the close of the Cretaceous. Present-day populations are largely Tertiary relicts with restricted, often fragmented ranges.
Ecology
Araucaria species typically occupy exposed or open-canopy sites — mountain ridgelines, forest margins, and maquis shrubland — where they can form emergent or co-dominant layers. New Caledonian species of section Eutacta have specialised for ultramafic substrates, tolerating soils rich in nickel and other heavy metals that are inhospitable to most plants. Their relatively recent adaptive radiation on these chemically extreme soils accounts for the high species diversity on the island.
The large, energy-rich seeds produced by several species are a critical food source for wildlife and humans. Paleo-ecological hypotheses suggest that sauropod dinosaurs' elongated necks may have evolved in part to browse the foliage of tall Jurassic Araucaria forests, given the leaves' high caloric content despite slow fermentation rates.
Cultivation
Several Araucaria species are grown as ornamental trees worldwide, valued for their formal, tiered branching architecture. A. heterophylla (Norfolk Island pine) is particularly popular as a potted indoor tree in temperate climates and as a street or garden tree in frost-free regions. A. araucana (monkey puzzle) is grown in temperate gardens and is awarded the RHS Award of Garden Merit.
A. angustifolia, where cultivated, thrives in humid subtropical conditions with annual temperatures of 18–23°C, full sun, moist but well-drained soil (pH 5.5–6.5), and annual rainfall of 1,500–2,000 mm. Mature trees can tolerate brief cold spells to −5°C, though new growth is damaged at 0°C. Multiple species supply commercially valuable timber used for construction, interior fittings, flooring, furniture, veneer, plywood, and pulp.
Conservation
Conservation status varies significantly across the genus. A. angustifolia (Paraná pine) is listed as Critically Endangered on the IUCN Red List, having suffered severe deforestation of its native subtropical forest in Brazil and Argentina. A. araucana is classified as Endangered, threatened by logging, fire, and climate-driven range contraction. Many of the 14 New Caledonian endemic species of section Eutacta occupy highly restricted ranges and face threats from mining, fire, and habitat loss, though formal IUCN assessments vary by species.
Cultural Uses
The large seeds of several Araucaria species have been a staple food for indigenous peoples for thousands of years. The Mapuche of Chile and Argentina harvest the seeds of A. araucana (called "piñones") as a key calorie source, particularly in autumn, and the species holds deep spiritual significance in Mapuche cosmology. In southern Brazil, the Kaingang people and other communities harvest the seeds of A. angustifolia (known as "pinhão"), which are boiled, roasted, or ground into flour. Indigenous Australians have long eaten the seeds of A. bidwillii (bunya nuts), traditionally gathering at bunya forests for large inter-group festivals.
Beyond food, the resin and extracts of various species have documented folk-medicinal applications, and research has identified anti-ulcer, antiviral, neuroprotective, antidepressant, and anticoagulant activities in genus extracts. The lightweight, straight-grained timber of A. angustifolia and A. cunninghamii has been commercially exploited for construction lumber, furniture, flooring, musical instruments, and paper pulp.
