**Botanical Information:**
– The genus Macadamia was named after John Macadam by Ferdinand von Mueller in 1857.
– Macadamia trees belong to the Proteaceae family and consist of four species.
– The trees can grow 2–12m tall and have lanceolate to obovate leaves.
– The flowers are white to pink or purple, with tough, woody fruits.
– Macadamia nuts require around 2000 N to crack and are cultivated for commercial production.
**Historical and Commercial Development:**
– Allan Cunningham first encountered the macadamia plant in Australia in 1828.
– The first commercial orchard was planted in New South Wales in 1888.
– Hawaii pioneered large-scale commercial production of macadamia nuts.
– South Africa became the world’s largest producer of macadamias in the 2010s.
– Australia surpassed the United States as the major producer in 1997.
**Cultivation and Cultivars:**
– Macadamia trees are propagated by grafting and start producing seeds at 7–10 years.
– They prefer fertile, well-drained soils with 1,000–2,000mm rainfall.
– Cultivars like Beaumont, Maroochy, Nelmac II, and Renown offer varying characteristics.
– Commercial orchards can yield up to 18kg per tree by 8 years old.
– Macadamia trees can bear fruit for over a century.
**Production and Distribution:**
– South Africa led macadamia nut production in 2018.
– Macadamias are commercially produced in Southeast Asia, South America, Australia, and North America.
– They thrive in climates ranging from Mediterranean to tropical.
– Lack of genetic diversity in commercial crops poses risks.
– Macadamia nuts are known for being the most expensive globally.
**Nutritional Information and Other Uses:**
– Raw macadamia nuts are high in fat and low in protein, rich in essential nutrients.
– Macadamia nuts contain monounsaturated fats, including omega-7 palmitoleic acid.
– Macadamias are toxic to dogs and cats, causing various symptoms.
– Besides consumption, macadamia trees are used ornamentally and for honey production.
– Macadamia seeds are fed to hyacinth macaws and used as food plants by certain larvae species.