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Macadamia nuts on tree.JPG
Macadamia nuts
Scientific classification edit
Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Order: Proteales
Family: Proteaceae
Subfamily: Grevilleoideae
Tribe: Macadamieae
Subtribe: Macadamiinae
Genus: Macadamia

Macadamia is a genus of four species of trees indigenous to Australia, and constituting part of the plant family Proteaceae.[1][2] They are native to north eastern New South Wales and central and south eastern Queensland. Three species of the genus are commercially important for their fruit, the macadamia nut /ˌmækəˈdmiə/ (or simply macadamia), with a total global production of 160,000 tonnes (180,000 short tons) in 2015.[3] Other names include Queensland nut, bush nut, maroochi nut, bauple nut, and Hawaii nut.[4] In Australian Aboriginal languages, the fruit is known by names such as bauple, gyndl, jindilli,[4] and boombera.

Fresh macadamia nut with husk or pericarp cut in half
Macadamia nut in its shell and a roasted nut
Macadamia nut with sawn nutshell, and special key used to pry open the nut


The German-Australian botanist Ferdinand von Mueller gave the genus the name Macadamia in 1857 in honour of the Scottish-Australian chemist, medical teacher, and politician John Macadam.[5]


Macadamia is an evergreen genus that grows 2–12 m (7–40 ft) tall.

The leaves are arranged in whorls of three to six, lanceolate to obovate or elliptic in shape, 6–30 cm (2–10 in) long and 3–13 cm (1–5 in) broad, with an entire or spiny-serrated margin. The flowers are produced in a long, slender, simple raceme 5–30 cm (2–10 in) long, the individual flowers 10–15 mm (0.4–0.6 in) long, white to pink or purple, with four tepals. The fruit is a hard, woody, globose follicle with a pointed apex, containing one or two seeds.


Allan Cunningham was the first European to discover the macadamia plant.[6]
German-Australian botanist Ferdinand von Mueller gave the genus the scientific name Macadamia – named after von Mueller’s friend Dr. John Macadam, a noted scientist and secretary of the Philosophical Institute of Australia.[7]
Walter Hill, superintendent of the Brisbane Botanic Gardens (Australia), observed a boy eating the kernel without ill effect, becoming the first nonindigenous person recorded to eat macadamia nuts.[8]
King Jacky, aboriginal elder of the Logan River clan, south of Brisbane, Queensland, was the first known macadamia entrepreneur, as his tribe and he regularly collected and traded the macadamias with settlers.[9]
Tom Petrie planted macadamias at Yebri Creek (near Petrie) from nuts obtained from Aboriginals at Buderim;[10]
William H. Purvis introduced macadamia nuts to Hawaii as a windbreak for sugar cane.[11]
The first commercial orchard of macadamias was planted at Rous Mill, 12 km from Lismore, New South Wales, by Charles Staff.[12]
Joseph Maiden, Australian botanist, wrote, "It is well worth extensive cultivation, for the nuts are always eagerly bought."[13]
The Hawaiian Agricultural Experiment Station encouraged planting of macadamias on Hawaii's Kona District, as a crop to supplement coffee production in the region.[14]
Tom Petrie begins trial macadamia plantations in Maryborough, Queensland, combining macadamias with pecans to shelter the trees.[15]
Ernest Van Tassel formed the Hawaiian Macadamia Nut Co in Hawaii.[16]
Tassel leased 75 acres (30 ha) on Round Top in Honolulu and began Nutridge, Hawaii's first macadamia seed farm.[17]
Tassel established a macadamia-processing factory on Puhukaina Street in Kakaako, Hawaii, selling the nuts as Van's Macadamia Nuts.
Winston Jones and J. H. Beaumont of the University of Hawaii's Agricultural Experiment Station reported the first successful grafting of macadamias, paving the way for mass production.[18]
Steve Angus, Murwillumbah, Australia, formed Macadamia Nuts Pty Ltd, doing small-scale nut processing.[19]
A large plantation was established in Hawaii.[20][21]
Castle & Cooke added a new brand of macadamia nuts called "Royal Hawaiian", which was credited with popularizing the nuts in the U.S.
Australia surpassed the United States as the major producer of macadamias.[14]
South Africa surpassed Australia as the largest producer of macadamias.[22][3]
Macadamia nuts were responsible for the delay of Korean Air Flight 86 at John F. Kennedy International Airport in New York City. This "nut rage incident" gave the nuts high visibility in the South Korean economy and marked a sharp increase in consumption there.[23][24]


Nuts from M. jansenii contain toxic amounts of cyanogenic glycosides,[25] The other three species are cultivated in the commercial production of macadamia nuts for human consumption.

Previously, more species with disjunct distributions were named as members of this genus Macadamia.[2] Genetics and morphological studies published in 2008 show they have separated from the genus Macadamia, correlating less closely than thought from earlier morphological studies.[2] The species previously named in the genus Macadamia may still be referred to overall by the descriptive, non-scientific name of macadamia.

Formerly included in the genus
Lasjia P.H.Weston & A.R.Mast, formerly Macadamia until 2008
  • Lasjia claudiensis (C.L.Gross & B.Hyland) P.H.Weston & A.R.Mast; synonym, base name: Macadamia claudiensis C.L.Gross & B.Hyland
  • Lasjia erecta (J.A.McDonald & R.Ismail) P.H.Weston & A.R.Mast; synonym, base name: Macadamia erecta J.A.McDonald & R.Ismail
  • Lasjia grandis (C.L.Gross & B.Hyland) P.H.Weston & A.R.Mast; synonym, base name: Macadamia grandis C.L.Gross & B.Hyland
  • Lasjia hildebrandii (Steenis) P.H.Weston & A.R.Mast; synonym, base name: Macadamia hildebrandii Steenis
  • Lasjia whelanii (F.M.Bailey) P.H.Weston & A.R.Mast; synonyms: base name: Helicia whelanii F.M.Bailey, Macadamia whelanii (F.M.Bailey) F.M.Bailey
Catalepidia P.H.Weston, formerly Macadamia until 1995
  • Catalepidia heyana (F.M.Bailey) P.H.Weston; synonyms: base name: Helicia heyana F.M.Bailey , Macadamia heyana (F.M.Bailey) Sleumer
Virotia L.A.S.Johnson & B.G.Briggs, formerly Macadamia until the first species renaming began in 1975 and comprehensive in 2008


Macadamia integrifolia flowers

Three of the four species—Macadamia integrifolia, Macadamia ternifolia, and Macadamia tetraphylla—are of commercial importance. The other species, M. jansenii, produces poisonous nuts resulting from toxic amounts of cyanogenic glycosides.[25]

The macadamia tree is usually propagated by grafting, and does not begin to produce commercial quantities of seeds until it is 7–10 years old, but once established, may continue bearing for over 100 years. Macadamias prefer fertile, well-drained soils, a rainfall of 1,000–2,000 mm (40–80 in), and temperatures not falling below 10 °C (50 °F) (although once established, they can withstand light frosts), with an optimum temperature of 25 °C (80 °F). The roots are shallow and trees can be blown down in storms; they are also susceptible to Phytophthora root disease.

Macadamia 'Beaumont' in new growth



A Macadamia integrifolia / M. tetraphylla hybrid commercial variety is widely planted in Australia and New Zealand; it was discovered by Dr. J. H. Beaumont. It is high in oil, but is not sweet. New leaves are reddish, and flowers are bright pink, borne on long racemes. It is one of the quickest varieties to come into bearing once planted in the garden, usually carrying a useful crop by the fourth year, and improving from then on. It crops prodigiously when well pollinated. The impressive, grape-like clusters are sometimes so heavy, they break the branchlets to which they are attached. In commercial orchards, it has reached 18 kg (40 lb) per tree by eight years old. On the downside, the macadamias do not drop from the tree when ripe, and the leaves are a bit prickly when one reaches into the interior of the tree during harvest. Its shell is easier to open than that of most commercial varieties.

Macadamia 'Maroochy' new growth


A pure M. tetraphylla variety from Australia, this strain is cultivated for its productive crop yield, flavor, and suitability for pollinating 'Beaumont'.

Nelmac II[edit]

A South African M. integrifolia / M. tetraphylla hybrid cultivar, it has a sweet seed, which means it has to be cooked carefully so that the sugars do not caramelise. The sweet seed is usually not fully processed, as it generally does not taste as good, but many people enjoy eating it uncooked. It has an open micropyle (hole in the shell) which may let in mould. The crack-out percentage (ratio of nut meat to whole nut, by weight) is high. Ten-year-old trees average 22 kg (50 lb) per tree. It is a popular variety because of its pollination of 'Beaumont', and the yields are almost comparable.


A M. integrifolia / M. tetraphylla hybrid, this is a rather spreading tree. On the plus side, it is high yielding commercially, 17 kg (37 lb) from a 9-year-old tree has been recorded, and the nuts drop to the ground. However, they are thick-shelled, with not much flavor.

Macadamia nuts, raw
Nutritional value per 100 g (3.5 oz)
Energy3,080 kJ (740 kcal)
13.8 g
Sugars4.57 g
Dietary fiber8.6 g
75.8 g
Saturated12 g
Monounsaturated59 g
Polyunsaturated1.5 g
7.9 g
VitaminsQuantity %DV
Thiamine (B1)
1.195 mg
Riboflavin (B2)
0.162 mg
Niacin (B3)
2.473 mg
Pantothenic acid (B5)
0.76 mg
Vitamin B6
0.275 mg
Folate (B9)
11 μg
Vitamin C
1.2 mg
Vitamin E
0.54 mg
MineralsQuantity %DV
85 mg
3.69 mg
130 mg
4.1 mg
188 mg
368 mg
1.30 mg

Percentages are roughly approximated using US recommendations for adults.


In 2018, South Africa was estimated to remain the world's leading producer of macadamia nuts with 54,000 tonnes out of global production of 211,000 tonnes.[26] In 2015, South Africa produced 48,000 tonnes (53,000 short tons) compared to Australia's 40,000 tonnes and the total global production of 160,000 tonnes (180,000 short tons).[3] Macadamia is also commercially produced in Brazil, California, Hawaii, Costa Rica, Israel, Kenya, China, Bolivia, New Zealand, Colombia, Guatemala and Malawi.

The first commercial orchard of macadamia trees was planted in the early 1880s by Rous Mill, 12 km (7.5 mi) southeast of Lismore, New South Wales, consisting of M. tetraphylla.[27] Besides the development of a small boutique industry in Australia during the late 19th and early 20th centuries, macadamia was extensively planted as a commercial crop in Hawaii from the 1920s. Macadamia seeds were first imported into Hawaii in 1882 by William H. Purvis, who planted seeds that year at Kapulena.[28] The Hawaiian-produced macadamia established the well-known seed internationally, and in 2017 Hawaii produced over 22,000 tonnes.[29]

Food and nutrition[edit]

The seeds (nuts) are a valuable food crop.

In a 100-gram amount, macadamia nuts provide 740 Calories and are a rich source (20% or more of the Daily Value, DV) of numerous essential nutrients, including thiamin (104% DV), vitamin B6 (21% DV), manganese (195% DV), iron (28% DV), magnesium (37% DV), and phosphorus (27% DV) (table). Macadamia nuts are 76% fat, 14% carbohydrates, including 9% dietary fiber, and 8% protein (table).

Compared with other common edible nuts, such as almonds and cashews, macadamias are high in total fat and relatively low in protein (table). They have a high amount of monounsaturated fats (59% of total content, table) and contain, as 17% of total fat, the monounsaturated fat, omega-7 palmitoleic acid.[30]

Toxicity in dogs[edit]

Macadamias are toxic to 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.[31] Depending on the quantity ingested and size of the dog, symptoms may also include muscle tremors, joint pain, and severe abdominal pain. In 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.[31]

Other uses[edit]

The trees are also grown as ornamental plants in subtropical regions for their glossy foliage and attractive flowers. Macadamia species are used as food plants by the larvae of some Lepidoptera species, including Batrachedra arenosella.

Macadamia seeds are often fed to hyacinth macaws in captivity. These large parrots are one of the few animals, aside from humans, capable of cracking the shell and removing the seed.[32]


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  2. ^ a b c Mast, Austin R.; Willis, Crystal L.; Jones, Eric H.; Downs, Katherine M.; Weston, Peter H. (July 2008). "A smaller Macadamia from a more vagile tribe: inference of phylogenetic relationships, divergence times, and diaspore evolution in Macadamia and relatives (tribe Macadamieae; Proteaceae)". American Journal of Botany. 95 (7): 843–870. doi:10.3732/ajb.0700006. ISSN 1537-2197. PMID 21632410. Retrieved 4 Apr 2013.
  3. ^ a b c "South Africa becomes king of macadamia nuts again". FreshPlaza. 14 April 2015. Retrieved 9 October 2016.
  4. ^ a b The Bopple Nut
  5. ^ Mueller, F.J.H. von (1857) Account of some New Australian Plants.Transactions of the Philosophical Institute of Victoria 2: 72 Type: Macadamia ternifolia F.Muell.[1]
  6. ^ Wilson, Bee (October 5, 2010). "The Kitchen Thinker: Macadamias". The Telegraph. Retrieved 11 July 2017.
  7. ^ Shigeura, Gordon T.; Ooka, Hiroshi (1984). Macadamia nuts in Hawaii: history and production (PDF). Honolulu, HI: University of Hawaii. p. 8.
  8. ^ McKinnon, Ross. Australian Dictionary of Biography. Canberra: National Centre of Biography, Australian National University.
  9. ^ McConachie, Ian (1980). "The Macadamia Story" (PDF). California Macadamia Society Yearbook. 26: 41–47. Retrieved 11 Jan 2014.
  10. ^ (Nut Growing Experiments’ The Queenslander Thursday 8 October 1931 p.13)
  11. ^ Hamilton, Richard; Ito, Philip; Chia, C.L. Macadamia: Hawaii's Dessert Nut (PDF). University of Hawaii. p. 3. Retrieved 10 July 2017.
  12. ^ Rosengarten, Frederic Jr. (2004). The Book of Edible Nuts. Courier Corporation. p. 122. Retrieved 10 July 2017.
  13. ^ Maiden, J. H., The Useful Native Plants of Australia, 1889, p40
  14. ^ a b Rieger, M., Introduction to Fruit Crops, 2006, p. 260. ISBN 978-1-56022-259-0
  15. ^ "Nut Growing Experiments". The Queenslander. October 8, 1931. p. 13.
  16. ^ Shigeura, Gordon; Ooka, Hiroshi (April 1984). Macadamia Nuts in Hawaii: History and Production (PDF). University of Hawaii. p. 13. Retrieved 10 July 2017.
  17. ^ Gordon T. Shigeura and Hiroshi Ooka. Macadamia Nuts in Hawaii: History and Production.
  18. ^ Jones, Winston; Beaumont, J.H. (Oct 1, 1937). "Carbohydrate accumulation in relation to vegetative propagation of the litchi". Science. 86 (2231): 313. Retrieved 10 July 2017.
  19. ^ "Macadamia History - Macadamia Castle". Macadamia Castle. Retrieved 2018-05-03.
  20. ^ Sandra Wagner-Wright (1995). History of the macadamia nut industry in Hawai'i, 1881–1981. E. Mellen Press. ISBN 978-0-7734-9097-0.
  21. ^ Mauna Loa Macadamia Nut Packaging
  22. ^ "Cracking good run for macadamia industry". Farmer's Weekly. Retrieved June 8, 2015.
  23. ^ Taylor, Adam. "Why 'nut rage' is such a big deal in South Korea". The Washington Post. Retrieved 10 July 2017.
  24. ^ Ahn, Young-oon. "Sales of macadamias soar in Korea after nut rage". CNBC. Retrieved 10 July 2017.
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  26. ^ Motaung, Ntswaki (2018-05-30). "More and more macadamia produced globally". Agriorbit. Retrieved 2019-01-15.
  27. ^ Macadamia Power Pty (1982). Macadamia Power in a Nutshell. Macadamia Power Pty Limited. p. 13. ISBN 978-0-9592892-0-6.
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  30. ^ "Macadamia nuts, raw, per 100 g". Conde Nast for the USDA National Nutrient Database, release SR 21. 2014. Retrieved 14 January 2016.
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  32. ^ Kashmir Csaky (November 2001). "The Hyacinth Macaw". Parrots Magazine. Retrieved December 6, 2010.

External links[edit]