The Wollemi Pine, scientifically named Wollemia nobilis, is native to a very specific and restricted area within the Wollemi National Park in New South Wales, Australia. This tree grows in a temperate rainforest within a series of narrow, steep-sided, sandstone gorges, roughly 150 km northwest of Sydney. The exact location remains undisclosed to protect this critically endangered species from threats like illegal collecting and to preserve its habitat. The environment where it thrives is characterized by high humidity, cool temperatures, and well-draining, acidic soils derived from sandstone.
The Wollemi Pine was only discovered in 1994 by David Noble, a park ranger, during a canyoning expedition in the Wollemi wilderness. This made headlines because Wollemia was thought to be extinct, with its closest known fossil relatives dating back over 90 million years. Noble had good botanical knowledge, and quickly recognised the trees as unusual because of the unique bark, and worthy of further investigation. The discovery was likened to finding a living dinosaur due to its “living fossil” status.
Immediately after its discovery, conservation measures were put in place to protect this rare species. It’s listed as critically endangered by the IUCN, with just a few dozen mature trees and several hundred juveniles known in the wild. Cloning and propagation programs were initiated to increase the population and spread the species in safe, controlled environments like botanic gardens worldwide. New trees were potted up in the Botanic Gardens of Sydney and Mount Annan and planted as far away as the Humboldt Botanical Garden near Eureka, California.
The tree has since become a symbol of conservation success, demonstrating the importance of preserving natural habitats. It has been used as a tool for education and raising awareness about biodiversity and the fragility of ecosystems. Australian officials have even gifted cloned Wollemi Pines to dignitaries as a symbol of environmental stewardship.
Wollemi Pine (Wollemia nobilis) Characteristics
Appearance
The Wollemi Pine is a visually striking tree, featuring dark green, needle-like leaves that are more flattened than those of typical conifers, giving the foliage a unique, almost fern-like appearance. The leaves are arranged in alternating spirals along the branches, which can differ in texture and shape between juvenile and adult stages. Juvenile leaves tend to be broader and have a different arrangement compared to the more needle-like adult foliage. The overall form of the tree can vary, sometimes appearing as a single trunk or, more commonly, as multiple trunks emerging from a single base due to its ability to coppice or regenerate from the base.
Size
In its natural habitat, Wollemia nobilis can grow to impressive heights of up to 40 meters (131 feet), with a trunk diameter reaching up to one meter (3.3 feet). However, in cultivation or under different conditions, it might not reach these maximum sizes, often growing to about 10-20 meters (33-66 feet) depending on the environment.
Bark
One of the most distinctive features of the Wollemi Pine is its bark, which has a unique texture resembling chocolate or Coco Pops cereal. It’s dark brown, with a bubbly or knobbly appearance, providing an unusual aesthetic that helps in identifying the tree. This bark also aids in fire resistance, an adaptation to its forest environment where wildfires are common.
Growth Rate
The growth rate of the Wollemi Pine is moderate to fast for a conifer of its type. Young trees can show significant growth in optimal conditions, with annual increases in height noted in cultivation. However, its growth can slow down as it matures, particularly in less than ideal conditions outside its native habitat.
Lifespan
While exact lifespan data is scarce due to the recent discovery of living specimens, its fossil record suggests that Wollemia nobilis can live for centuries. Given the longevity of similar conifers, it’s plausible that these trees could live for several hundred years or more, especially in their natural, protected environments.
Reproduction
The Wollemi Pine is dioecious, meaning there are separate male and female trees. Male trees produce small, pollen-producing cones, while female trees bear much larger, seed-bearing cones. These cones are quite distinctive; female cones can be sizable, woody, and spiny, facilitating seed dispersal when they open. The seeds need specific conditions to germinate, often requiring a period of cold stratification to break dormancy. However, propagation through cuttings has proven successful, aiding in conservation efforts.
Root System
Wollemia nobilis has a robust root system adapted to its native sandstone soils, which are often nutrient-poor but well-draining. It has a characteristic ability to regenerate from the base after damage, which includes the capacity to send out new shoots or even new trunks from the root system or lower trunk, demonstrating a form of coppicing. This adaptation is particularly useful in surviving fires or other disturbances, allowing the tree to regenerate from what might seem like total destruction.
USDA Zones
The Wollemi Pine is suitable for USDA Hardiness Zones 8 to 11, reflecting its ability to adapt to a range of climates from warm temperate to subtropical. In Zone 8, where winters can be colder, it might need some protection from extreme frosts, particularly when young. In Zones 9 through 11, it can thrive with less worry about cold, although care must be taken to ensure the soil remains well-drained and the tree isn’t subjected to prolonged drought or excessive heat without water.
Cultivation
- Site Selection: When considering planting a Wollemi Pine, choose a site with partial shade to full sun, mimicking its natural habitat’s dappled light conditions. It prefers acidic, well-draining soil, ideally sandy or loamy to prevent waterlogging, which can be detrimental. Given its potential size, ensure there’s ample space for growth.
- Soil and Planting: The soil should be well-aerated and slightly acidic. Amend heavy soils with sand or organic matter to improve drainage. Planting should occur in spring, giving the tree time to establish before winter, or in early fall to benefit from autumn rains.
- Watering: While established trees are somewhat drought-tolerant, young Wollemi Pines need regular watering to develop a strong root system. Water deeply but infrequently to encourage deep root growth, and reduce watering in winter when growth slows.
- Maintenance: Pruning is generally unnecessary except for removing dead or damaged branches. However, shaping can be done in its early years to promote a desirable form. Keep an eye out for pests like scale insects or fungal diseases in overly wet conditions.
- Growth Rate: With the right conditions, growth can be relatively fast for a conifer, though it will slow as the tree matures. Fertilizing once a year with a slow-release, balanced fertilizer can support healthy growth.
- Propagation: Most propagation is done through cuttings due to the ease and success rate compared to seeds. Cuttings should be taken from new growth, treated with rooting hormone, and kept in a controlled environment until rooted.
Landscape Uses
- Specimen Plant: Due to its rarity and unique appearance, the Wollemi Pine serves as an exceptional focal point in landscapes, botanical gardens, or arboretums. Its prehistoric charm can be a conversation starter and educational tool.
- Architectural Feature: Its form, with multiple trunks or the potential for a single majestic trunk, makes it an architectural element in garden design, especially when planted where its unusual bark can be appreciated.
- Conservation Symbol: Planting a Wollemi Pine can symbolize commitment to conservation, as each tree represents a small step in securing the future of this critically endangered species.
- Urban Landscapes: In cities within its suitable zones, it can be used in parks, larger gardens, or as part of urban forest initiatives, offering both beauty and a nod to environmental stewardship.
- Educational Gardens: Its story of rediscovery and survival makes it a perfect subject for educational settings, where it can teach about plant evolution, conservation, and the importance of protecting natural habitats.
- Screening or Hedging: Although not as fast-growing as some species used for this purpose, in time, a row of Wollemi Pines can provide a unique, dense screen due to their foliage density and growth habit.