Other Names:Bauple nut, bush nut, Hawaii nut and Maroochy nut.
Summary:A small to medium sized tree, with opposite, glossy leaves in sets of 3-4 usually. The flowers are white to pink. Macadamia integrifolia and its hybrids are the species most commonly cultivated for its fruit.
Leaves:Macadamia tetraphylla - Leaves mostly in whorls of 4 (rarely 3 or 5), base very obtuse, sessile or petioles less than 3 mm, new growth reddish.
Flower head:Flowers in pairs and sessile. Axillary and produced on the woody branches of last seasons growth (ramiflorous).
Flowers:Ovary - Sessile, hairy, 2 ovules. Style thread like and elliptical at the top.
Fruit:Single, spherical, smooth. 20-35 mm diameter, greyish green turning brown.
Seeds:15-30 mm, pointed at the tip and lumpy.
Key Characters:Whorled leaves, young shoots glabrous.
Physiology:In 100-gram sample, macadamia nuts have 740 calories and are a rich source of numerous essential nutrients, including thiamine, vitamin B6, manganese, iron, magnesium, and phosphorus. Macadamia nuts are 76% fat, 14% carbohydrates, 8% protein and 9% fiber.
Reproduction:Mainly propagated by grafting
Flowering times:Macadamia tetraphylla - August-October. Fruit ripe in January.
Seed Biology and Germination:
Vegetative Propagules:Often grafted.
Hybrids:A Macadamia integrifolia x Macadamia tetraphylla hybrid is a common commercial variety that is widely planted in Australia and New Zealand and bears useful amounts of fruit after it is four years old.
Allelopathy:Ecology, Population Dynamics and Dispersal:
Origin and History:Native to New South Wales and Queensland in Australia
Distribution:NSW, QLD, TAS, VIC.
Soil:Prefer fertile, well-drained soils.
Toxicity:Toxic to dogs.
Symptoms:In dogs, ingestion may result in macadamia toxicity marked by weakness and hind limb paralysis with the inability to stand, occurring within 12 hours of ingestion. Depending on the quantity ingested and size of the dog, symptoms may also include muscle tremors, joint pain, and severe abdominal pain.
Treatment:For high doses of toxin, opiate medication may be required for symptom relief until the toxic effects diminish, with full recovery usually within 24 to 48 hours.
Management and Control:Manual removal.
Eradication strategies:Manual removal.
Herbicide resistance:None reported.
Biological Control:The caterpillars of some Lepidoptera feed on the leaves.
Related plants:Macadamia jansenii produces poisonous nuts containing toxic amounts of cyanogenic glycosides
Plants of similar appearance:
References:Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).