Paraná pine
A close relative of the more commonly grown monkey puzzle tree (Araucaria araucana), the Paraná pine is facing an uncertain future. Native to southern parts of Brazil (including the state of Paraná) and adjacent parts of Argentina and Paraguay, mature Paraná pines dominate araucaria forest. Since 1900, it is estimated that the total area of araucaria forest has declined by 97%, with only 565,419 ha remaining in 1982, when logging was still continuing at an estimated rate of 80,000 ha per year.
The Paraná pine is listed by the International Union for Conservation of Nature Red List of Threatened Species as Critically Endangered. This is only one step away from extinction. It is the most important timber tree in Brazil but also under pressure from land clearance for other faster growing timber species. In addition to the massive exploitation for timber, 3,400 tonnes of seeds are collected annually for human consumption. The seeds, or pinhões (singular pinhão) as they are known in Portuguese, are boiled before consumption and are so popular that the annual Festa do Pinhão, in the city of Lages, Santa Catarina (Brazil) is dedicated to them!
Extracts of this tree have traditionally been used in Brazil to treat sexually transmitted diseases, shingles and wounds. Scientists have found these extracts to have anti-viral activity in laboratory tests, although there is more than one component contributing to the activity. Other substances in this tree have shown potential as anti-epilepsy drug candidates.
The seeds take about four years to form and mature, once the ovules have been fertilised following pollination. Yet once the seeds disperse and fall to the ground, they only remain viable for a few weeks, usually germinating as soon as they fall from the tree. These trees, which are not technically pines but they are conifers, are normally dioecious (Greek: two households), meaning they have male and female reproductive parts on separate trees. Pollination is achieved by the wind blowing pollen from male trees to female trees. Trees start to set seed as teenagers. The Araucaria angustifolia growing at Harcourt Arboretum is still a youngster and we are yet to establish if it is male or female.
Surprisingly perhaps, for a tree native to the sub-tropics, it has proven to be hardy outside in Oxfordshire. Although in its native habitat it will experience temperatures below 0 °C, the coldest average monthly temperature it experiences is 8-12 °C.
Further reading
Bittencourt JVM 2007. Araucaria angustifolia - its geography and ecology. Geographical Paper 180. Department of Geography, University of Reading.
Thomas P 2013. Araucaria angustifolia. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1.
Alison Foster