Tree of the month - Wollemi Pine

Posted on: 28 May 2024

This tree is new to campus and we’re excited to now have three of them: one in front of the Chemistry Building, one in New Square and one in the Provost’s garden. Ours are young and only stand at about 1.5 metres high, with a girth about the size of a plum. When mature, they can reach 40m in height with girths of 1m and can live for 500-1000 years.  Owning and caring for these trees contributes to the conservation of this endangered species. 

The Wollemi Pine nearly disappeared towards the end of the Cretaceous period in the northern hemisphere. This was due to flowering plants becoming more dominant, the supercontinent of Gondwana breaking up, and varying climatic conditions. There are estimated to be less than one hundred mature adult plants left in the wild and thus it is the focus of extensive research and conservation. Devastating wildfires burned a huge portion of Wollemi National Park in 2019-20, but thankfully a firefighting operation managed to save the remaining trees from near extinction. Bush fires still represent a daily threat to this small natural population in the wild.

Interestingly, the Wollemi Pine has twenty-six chromosomes, containing 12.2 billion base pairs, compared to humans who have around three billion. However, the Wollemi pine remains low in genetic diversity, which is linked to the dramatic population decline thousands of years ago and limited exchange of genetic information. The Wollemi pine has embraced another reproductive strategy involving self-coppicing or producing suckers, which may also be part of the reason for the lower genetic diversity.

Wollemi Pine (although not a true pine tree) have young leaves that are dark green and fern like, while the adults are stiffer, flattened and more blue green in colour. Wollemi Pine is monoecious meaning male and female cones occur on the same tree but on different branches, known as meagasporangiate (female) and mircosporangiate (male). The male cones are long and cylindrical and produce pollen while the female cones are large, globose and produce the seed. The bark is quite unique as well with its bubbly texture and chocolate brown colour.

These trees can grow 20-30cm per year and will be cared for during the growing season, especially when flushing new growth.  Trinity College Botanic Gardens also have a potted specimen as well as its close relations, Araucaria and Agathis. We hope you can visit one of our beautiful new Wollemi pines.

Thanks to John Parnell and Stephen Waldren for providing this information and caring for our trees.  

• Tags:
• Environment
• Sustainability