The genus Araucaria was part of terrestrial flora since the Triassic and found its apogee in Gondwana. Today, it is restricted to the Southern Hemisphere and has 19 species.
Distribution
Covering an original area of, it has now lost an estimated 97% of its habitat to logging, agriculture, and silviculture. It is native to southern Brazil. According to a study made by the Brazilian researcher Maack, the original area of occurrence represented 36.67% of the Paraná state, 60.13% of the Santa Catarina state, 21.6% of the São Paulo state and 17.38% of the Rio Grande do Sul state. It is also found in the northeast of Argentina, locally in Paraguay, growing in low mountains at altitudes of and in northern regions of Uruguay where it was thought to be extinct until recent discoveries. The prehistoric distribution of A. angustifolia in earlier geologic periods was very different to the present day, fossils were found in the Northeast Region, Brazil. The present day range is recent, the species moving into this area during the later Pleistocene and early Holocene. This chorological shift may possibly be due to climatic change and the migration of mountain flora by way of river courses.
Description
It is an evergreen tree growing to tall and diameter at breast height. However, the largest individual, near Nova Petropolis, Rio Grande do Sul State, Brazil is 147.7 feet in height with a D.B.H. of 12.5 feet. The leaves are thick, tough and scale like, triangular, long, broad at the base, and with razor-sharp edges and tip. They persist 10 to 15 years, so cover most of the tree except for the trunk and older branches. It is closely related to Araucaria araucana from further southwest in South America, differing most conspicuously in the narrower leaves. It is usually dioecious, with the male and femalecones on separate trees. The male cones are oblong, long at first, expanding to long by broad at pollen release. Like all conifers it is wind pollinated. The female cones, which mature in autumn about 18 months after pollination, are globose, large, in diameter, and hold about 100–150 seeds. The cones disintegrate at maturity to release the approximately long nut-like seeds, which are then dispersed by animals, notably the azure jay, Cyanocorax caeruleus. The inner bark and resin from the trunk of the tree is reddish, which can be a good defining character because it differs from A. araucana, which has brown bark inner and white resin.
Habitat and ecology
It prefers well drained, slightly acidic soil but will tolerate almost any soil type provided drainage is good. It requires a subtropical climate with abundant rainfall, tolerating occasional frosts down to about. . The seeds are very important for the native animals. Several mammals and birds eat pinhão, and it has an important ecological role in Araucaria moist forests. In a long term study observing the feeding behaviour throughout the year of the squirrel Guerlinguetus brasiliensis ssp. ingrami in a secondary A. angustifolia forest in the Parque Recreativo Primavera in the vicinity of the city ofCuritiba, Paraná, of the ten plant species of which the squirrel ate the seeds or nuts, seeds of A. angustifolia were the most important food item in the fall, with a significant percentage of their diet in the winter consisting of the seeds as well. The squirrels cache seeds, but it is unclear how this affects recruitment.
Human use
It is a popular garden tree in subtropical areas, planted for its unusual effect of the thick, 'reptilian' branches with a very symmetrical appearance. The seeds, similar to large pine nuts, are edible, and are extensively harvested in southern Brazil, an occupation particularly important for the region's small population of natives. The seeds, called pinhão are popular as a winter snack. The city of Lages, in Santa Catarina state, holds a popular pinhão fair, in which mulled wine and boiled Araucaria seeds are consumed. of seeds are collected annually in Brazil. It is also used as a softwood timber in stair treads and joinery. The species is widely used in folk medicine.
Conservation
According to one calculation it has lost an estimated 97% of its habitat to logging, agriculture, and silviculture in the last century. People also eat the seeds, which may reduce recruitment. It was therefore listed by the IUCN as 'vulnerable in 1998 and 'critically endangered' in 2008.
