Scientific name: Macadamia tetraphylla
Other names: Queensland Nut, Rough-shelled Bush Nut
- National: Vulnerable (EPBCA 1999)
- Queensland: Vulnerable (NCA 1995)
What does it look like?
The Rough-shelled Macadamia is a small to medium-sized tree, densely branched and bushy, growing up to 18-20m tall. The leaves are 7-25cm long, oblong shaped and occur in whorls of four. The edges of the leaves have stiff prickly teeth and they are leathery in texture.
New growth is often pink to reddish in colour. The flowers are a creamy pink to purplish colour, hanging in long strings among the leaves. Flowering occurs between August and October and fruit between January and April.
The fruit is woody brown and globular with edible seeds enclosed in a hard, wrinkled, brown shell inside a round green husk. Vegetative resprouting and new seedlings have been recorded following habitat damage.
Where is it found?
Within Australia, populations of the Rough-shelled Macadamia are found in northeast New South Wales and South East Queensland. It occurs in subtropical rainforest in coastal areas, growing on moderate-steep hill slopes at well-drained sites.
What is threatening it?
- Habitat clearing and fragmentation
- Risk of local extinction
- Grazing and trampling by domestic stock
- Invasion of habitat by weeds
- Loss of local genetic strains through hybridisation with commercial varieties
- Reduced gene flow and reduction of genetic diversity.
The Rough-shelled Macadamia is protected under the Nature Conservation Act 1992 and the Environment Protection and Biodiversity Conservation Act 1999 . It is an offence to damage or interfere with the Rough-shelled Macadamia in any other way than when accepted by the respective Acts.
Redland City Council manages environmental weeds throughout the Redlands to minimise their impact on native ecosystems and plants such as the Rough-shelled Macadamia.
Did you know...?
The Rough-shelled Macadamia is native to Australia but grown worldwide for commercial use. It is utilised for the oil in its seeds and as a food source.
Rough-shelled Bush Nut is estimated to have a lifespan of over 100 years, with a juvenile period greater than six years. The species reproduces from seed and seed dispersal is via streams and small rodents.
How you can help
Manage environmental weeds on your property - see IndigiScapes’ brochure entitled Environmental Weeds of the Redlands [PDF 58MB] or visit the centre for advice on how to remove them and stop them from spreading.
If you have seen or suspect the Rough-shelled Macadamia at any location, please report it to IndigiScapes on (07) 3824 8611.