Southern Sassafras (AUS)

Basic Information

Common Name: Southern Sassafras (AUS)
Scientific Name: Atherosperma
Native Habitat: Native to the cool temperate rainforests and wet forests of southeastern Australia, including Tasmania, Victoria, and parts of New South Wales.

History / Discovery / Cultivator

The genus Atherosperma, particularly the species Atherosperma moschatum (commonly known as Southern Sassafras or Tasmanian Sassafras), holds a significant place in the botanical history and ecology of southeastern Australia. Belonging to the family Atherospermataceae (sometimes placed in Monimiaceae), this tree is an important component of the region’s unique cool temperate rainforest ecosystems.

The formal scientific description of Atherosperma moschatum was made by the French botanist Jacques Labillardière. Labillardière was part of the expedition led by Antoine Bruni d’Entrecasteaux which searched for the lost explorer La Pérouse in the early 1790s. During this voyage, Labillardière extensively collected plant specimens in Tasmania and and other parts of Australia, contributing immensely to the European understanding of the continent’s flora. His detailed work, Nova Hollandiae Plantarum Specimen, published between 1804 and 1806, included the description of Atherosperma moschatum in 1806. The genus name Atherosperma derives from Greek words meaning “awned seed,” referring to the bristly parachute-like structures attached to the seeds that aid in wind dispersal. The species epithet moschatum refers to the musky scent of the bark and wood.

Prior to European discovery and classification, Southern Sassafras was undoubtedly known and utilized by Indigenous Australian peoples within its range. While specific widespread traditional uses are not extensively documented in readily available sources compared to some other plants, rainforest resources were integral to Indigenous life. The fragrant bark and wood likely had traditional applications, although detailed records of these are often sparse or held within oral traditions.

In the context of European settlement, Atherosperma moschatum quickly gained recognition for its valuable timber. The wood, often beautifully figured with grey, brown, green, pink, or creamy streaks, became highly prized for cabinet making, furniture, woodturning, and decorative veneers. This led to logging of the tree in suitable rainforest areas, impacting its populations in some locations, although it remains common in many protected areas.

As a cultivated plant, Southern Sassafras is not typically grown as a houseplant due to its size and specific environmental needs. Its cultivation is primarily limited to outdoor settings in cool temperate climates where it receives sufficient moisture and humidity, often used as an ornamental tree in parks or large gardens. Its growth can be relatively slow, and it requires specific conditions that mimic its native rainforest habitat – consistently moist, well-drained, acidic soil, and protection from hot, dry winds and severe frost, particularly when young. Cultivation from seed can be challenging due to germination requirements (stratification), and propagation from cuttings is often difficult, making it less commonly propagated by home gardeners. Thus, its journey from a rainforest tree known to Indigenous peoples and discovered by early European botanists has led to its appreciation primarily as a source of unique timber and a distinctive, albeit regionally specific, ornamental tree rather than a globally cultivated garden or houseplant.

Plant Care Summary

Botanical Insights

Adaptations

Atherosperma moschatum exhibits several adaptations suited to its cool temperate rainforest habitat. Its evergreen foliage allows for continuous photosynthesis throughout the year in a climate where temperatures remain relatively mild. The tree thrives in areas with high rainfall and humidity, often in sheltered gullies, indicating adaptations for moisture retention and tolerance of consistently wet (but not waterlogged) soil conditions. The flowers are fragrant and relatively inconspicuous but are adapted for pollination, though specific pollinators are not always widely documented. The most notable adaptation is perhaps in its fruit and seed structure: the fruit is a cluster of small achenes (dry, single-seeded fruits), each tipped with a feathery, persistent style that acts as a parachute, facilitating wind dispersal of the seeds away from the parent tree to potentially less competitive locations within the forest understory or clearings. The bark is also relatively thin and smooth compared to trees in drier climates, characteristic of species adapted to moist environments where thick, insulating bark is less critical.

Propagation Methods

Propagating Atherosperma moschatum can be challenging, which contributes to it being less widespread in cultivation than some other native trees. The most reliable method is often from fresh seed. However, the seeds require stratification – a period of cold and moist conditions – to break dormancy, mimicking the natural winter cycle they would experience on the forest floor. Sowing fresh seed in autumn or subjecting collected seed to artificial cold stratification (e.g., storing in a refrigerator in moist sand) for several months is typically required. Germination can still be slow and variable. Propagation from cuttings is notoriously difficult with Southern Sassafras. Semi-hardwood cuttings taken in summer can sometimes be successful, but strike rates are often low, even with the use of rooting hormones and controlled environments (like mist beds). Air layering is another potential method, but it is also not guaranteed and is more labor-intensive. Due to these difficulties, commercial propagation may also involve grafting in some instances.

Toxicology

The bark of Atherosperma moschatum contains several biologically active alkaloids, the most prominent being atherospermine. Historically, the bark and leaves have been used in traditional medicine, particularly for respiratory ailments such as asthma due to the presence of these compounds, which can have bronchodilatory effects. However, like many alkaloid-containing plants, Atherosperma also possesses toxic properties if ingested in sufficient quantities. While information on the specific effects on common pets (cats, dogs) is not as widely available as for more common toxic plants, based on the presence of alkaloids, ingestion by animals or humans is likely to cause gastrointestinal upset, including vomiting, diarrhea, and abdominal pain. In larger doses, or depending on the specific alkaloid concentration and individual sensitivity, more serious systemic effects are theoretically possible due to the influence of alkaloids on various physiological processes, including cardiovascular and nervous systems, although severe poisonings from casual ingestion are not commonly reported. As a general precaution, it should be considered potentially toxic, and ingestion by pets or humans should be discouraged.

Common Problems

Pests:

• Wood-boring insects (attack stressed or damaged trees)
• Scale insects (can weaken plants if infestations are severe)
• Mites (less common but can occur in dry conditions)

Diseases:

• Root rot (caused by Phytophthora or other fungi in poorly drained or waterlogged soils)
• Fungal leaf spots (can occur in prolonged wet or humid conditions, usually not severe)
• Armillaria root rot (Honey Fungus) – a general forest pathogen that can affect weakened trees

Other:

• Poor growth or scorching (caused by drought, hot dry winds, or low humidity, unlike its preferred moist environment)
• Leaf yellowing (can indicate nutrient deficiency, poor drainage, or soil that is too alkaline)
• Failure to establish (can be challenging to transplant and requires specific soil and moisture conditions to thrive)

Rarity & Value

Rarity:

Within its native range in the cool temperate rainforests of Tasmania, Victoria, and New South Wales, Atherosperma moschatum is generally considered common within its specific habitat type. It is a characteristic and often dominant tree species in these particular ecosystems. However, the habitats themselves (cool temperate rainforests) have faced pressure from logging and land clearing in the past, which could impact local populations. Outside of these specific regions and suitable cool temperate climates, the tree is relatively rare in cultivation due to its specific environmental requirements and the difficulties associated with its propagation compared to more adaptable species. It is not typically considered a rare plant from a global conservation perspective, but its presence is limited to its native environmental niche and areas with similar climates where it can be successfully grown.

Value:

The value of Atherosperma moschatum is multifaceted. Economically, its primary value has historically been its timber. Southern Sassafras wood is highly prized in Australia for its attractive grain, unique colour variations (often displaying grey, brown, green, pink, and creamy streaks known as ‘figure’), and relative ease of working. It is used for furniture, cabinetry, decorative veneers, woodturning, and joinery. Ecologically, the tree holds significant value as a key component of cool temperate rainforest ecosystems, providing habitat and contributing to the biodiversity of these areas. Aesthetically, mature trees are valued in suitable landscapes for their form and fragrant flowers. It does not typically hold significant value as a collectible ‘rare plant’ in the horticultural sense, unlike many tropical houseplants with sought-after variegation or unusual forms, but its value lies more in its ecological importance and the utility and beauty of its timber.