Wollemia nobilis

Location & distribution maps

Plant description

Common name:                Wollemi pine  

Conservation status:                  

• The Wollemi pine is classified as critically endangered (CR) on the IUCN's Red List,and is legally protected in Australia

Etymology:   

• The genus is named after the Wollemi National Park in NSW

• The specific epithet is is after its discoverer, David Noble

Trunk:          

• It is an evergreen tree reaching 25–40 m tall

• The bark is very distinctive, dark brown, and knobbly, quoted as resembling the breakfast cereal Coco Pops

• The tree coppices readily, and most specimens are multiple-trunked or appear as clumps of trunks thought to derive from old coppice growth, with some consisting of up to 100 stems of differing sizes

• The branching is unusual in that nearly all the side branches never have further branching

• After a few years, each branch either terminates in a cone (either male or female) or ceases growth

• After this, or when the cone becomes mature, the branch dies

• New branches then arise from dormant buds on the main trunk

• Rarely, a side branch will turn erect and develop into a secondary trunk, which then bears a new set of side branches.

Cone & seeds:                         

• The seed cones are green, 6–12 cm long and 5–10 cm in diameter, and mature about 18–20 months after wind pollination

• They disintegrate at maturity to release the seeds which are small and brown, thin and papery with a wing around the edge to aid wind-dispersal

• The male (pollen) cones are slender conic, 5–11 cm long and 1–2 cm broad and reddish-brown in colour and are lower on the tree than the seed cones

• Seedlings appear to be slow-growing and mature trees are extremely long-lived; some of the older individuals today are estimated to be between 500 and 1 000 years 

Leaves:         

•  The leaves are flat linear, 3–8 cm long and 2–5 mm  broad

• They are arranged spirally on the shoot but twisted at the base to appear in two or four flattened ranks

• As the leaves mature, they develop from bright lime-green to a more yellowish-green

Stem & branches: 

• The bark is very distinctive, dark brown, and knobbly

• The tree coppices readily, and most specimens are multiple-trunked or appear as clumps of trunks thought to derive from old coppice growth, with some consisting of up to 100 stems of differing sizes

• The branching is unusual in that nearly all the side branches never have further branching

• After a few years, each branch either terminates in a cone (either male or female) or ceases growth

• After this, or when the cone becomes mature, the branch dies

• New branches then arise from dormant buds on the main trunk

• Rarely, a side branch will turn erect and develop into a secondary trunk, which then bears a new set of side branches

Habit:        

• It is a coniferous, evergreen tree reaching 25–40 m

Habitat:   

• Temperate rainforest 

Distribution:                  

•  In the Wollemi National Park northwest of Sydney in NSW

Additional notes:        

• Discovery & recovery plan

  • It was known only through fossil records until 1994, when the Australian species Wollemia nobilis was discovered in a temperate rainforest wilderness area of the Wollemi National Park in NSW

  • It was growing in a remote series of narrow, steep-sided, sandstone gorges 150 km north-west of Sydney

  • After it was discovered that the trees could be successfully cloned, new trees were potted up in the Botanic Gardens of Sydney and Mount Annan

  • A Recovery Plan has been drawn up, outlining strategies for the management of this fragile population - the overall objective is to ensure that the species remains viable in the long term

  • Australian prime ministers and foreign affairs ministers have presented Wollemi pines to various dignitaries around the world

• Discovery

  • The discovery, on or about 10 September 1994, by David Noble, Michael Casteleyn, and Tony Zimmerman, only occurred because the group had been systematically exploring the area looking for new canyons

  • Noble had good botanical knowledge, and quickly recognised the trees as unusual because of the unique bark and worthy of further investigation

  • He took specimens to work for identification, expecting someone to be able to identify the plants.

  • His specimens were identified by Wyn Jones, a botanist with National Parks and Jan Allen from the Botanical Gardens

  • After the identification was made, National Parks then went under a veil of secrecy, with the discoverers not learning the full magnitude of their discovery for about six months

  • National Parks came close to damaging the stand when a helicopter being used to collect cones inadvertently pruned one of the pines with its rotor

• Relationship to other conifers

  • Further study would be needed to establish its relationship to other conifers

  • The initial suspicion was that it had certain characteristics of the 200-million-year-old family Araucariaceae, but was not similar to any living species in the family

  • Comparison with living and fossilised Araucariaceae proved that it was a member of that family, and it has been placed into a new genus, beside the genera Agathis and Araucaria

• Fossils

  • Fossils closely resembling Wollemia that are thought to be related to it are widespread in Australia, New Zealand and Antarctica from Cretaceous era sediments, but Wollemia nobilis is the sole living member of its genus

  • These trees remained common throughout eastern Australia until around 40 million years ago but then gradually declined in range and abundance

  • Before the relict population was discovered in Wollemi National Park, the most recent known fossils of the genus date from approximately 2 million years ago in Tasmania

  • It is thus described as a living fossil or, alternatively, a Lazarus taxon

• Trees in the wild

  • Fewer than a hundred trees are known to be growing wild, in three localities not far apart

  • It is very difficult to count individuals, as most trees are multistemmed and may have a connected root system

  •  Genetic testing has revealed that all the specimens are genetically indistinguishable, suggesting that the species has been through a genetic bottleneck in which its population became so low (possibly just one or two individuals) that all genetic variability was lost.

• Threats

  • In November 2005, wild-growing trees were found to be infected with Phytophthora cinnamomi

  • NSW park rangers believe the virulent water mould was introduced by unauthorised visitors to the site, the location of which is still undisclosed to the public

  • The grove of Wollemia trees was endangered by fire during the 2019-20 Australian bushfire season

  • They were saved by specialist firefighters from the National Parks and Wildlife Service, supported by the Rural Fire Service who installed an irrigation system as well as dropping retardant

• Cultivation and uses

• A propagation programme made Wollemi pine specimens available to botanical gardens, first in Australia in 2006 and subsequently throughout the world. 

• It may prove to be a valuable tree for ornament, either planted in open ground or for tubs and planters. In Australia, potted native Wollemi pines have been promoted as a Christmas tree.

• It is also proving to be more adaptable and cold-hardy than its restricted temperate-subtropical, humid distribution would suggest, tolerating temperatures between −5 and 45 °C, with reports, from Japan and the USA, that it can survive down to −12 °C.

• A grove of Wollemi pines planted in Inverewe Garden, Scotland, believed to be the most northerly location of any successful planting, have survived temperatures of −7 °C, recorded in January 2010.

•  It also handles both full sun and full shade. 

• Like many other Australian trees, Wollemia is susceptible to the pathogenic water mould Phytophthora cinnamomi, so this may limit its potential as a timber tree.

• The Royal Botanic Gardens in Sydney have published information on how to grow Wollemi Pines from seed which has been harvested from helicopters from the forest trees. 

• The majority of seeds that fall from the cone are not viable so need to be sorted to retain the plump and dark ones. These can then be sown on top of seed raising mix and watered. Once the water has drained through the mix, the pot should be placed in a plastic bag and refrigerated for two weeks. After this, the pot should be removed from the plastic bag and placed somewhere warm but not very sunny until the seed germinates (remembering to keep them moist but not wet). This could take several months.Examples of the species can be viewed at The Tasmanian Arboretum.

• Care

• The Wollemi Pine is extremely hardy and versatile in cultivation. 

• Despite it being an endangered species, it is easy to grow and requires relatively low maintenance. It will adapt to a diverse range of climatic zones, thriving in full sun to semi shaded outdoor positions. They can be maintained in a pot almost indefinitely, and makes a good container plants for patios, verandas, and courtyards. Because it tolerates air conditioning, it can also be used as an indoor decorative plant. These are basic need to knows for care:[

  • Pruning

    • When pruning the Wollemi pine, use sterile secateurs at any time of year to retain its compact form

    • It can be pruned heavily with up to two thirds of the plant size removed

    • Pruning heavily can be done on the apical growth and the branches

    • The best time to prune is during the winter months

  • Growth rate

    • The Wollemi Pine has very controlled growth, especially if it is kept in a pot

    • It may take up to 25 years to reach 7 m in height

Sources of information:

• https://en.wikipedia.org/wiki/Wollemia (2023)