Brazil Nut Tree: The Sovereign Queen of the Amazon
Learn more about one of the largest trees in the Amazon, also known as the Amazon nut tree or Pará nut tree.
CRIA - Centro de Referência em Informação Ambiental
Fernando B. Matos
Mixed nuts (May 13, 2013) by Hedi AghlaraOriginal Source: Wikimedia Commons
Brazil nut
Most people know the “Brazil nut” as the largest nut in a nut mix. However, most don’t know that it comes from an Amazonian tree of the same name, or that it is actually a seed, not a nut.
Alexander von Humboldt and Aimé Bonpland in the Amazon jungle (1856) by Eduard EnderOriginal Source: Wikimedia Commons
The naturalists Humboldt and Bonpland
Long before it was recorded by European science, the Brazil nut tree was known and used by Indigenous peoples of the Amazon. In 1808, it was described as Bertholletia excelsa by Humboldt and Bonpland, based on specimens they collected on the banks of the Orinoco River.
A large tree
It is one of the largest trees in the Amazon, reaching between 30 and 50 m in height. Although discovered in Venezuela, the species became known worldwide as the “Brazil nut,” as Brazil has always been one of the main exporters of its seeds.
Mapa dos castanhais na bacia amazônica (October 17, 2019) by National GeographicOriginal Source: National Geographic
Distribution of the Brazil nut tree
Besides Brazil and Venezuela, the Brazil nut tree also occurs in the Amazonian regions of Colombia, Guyana, Peru, and Bolivia. Small plantations have been established in Malaysia and Ghana, and the species can be found in various botanical gardens around the world (e.g., Hawaii, Florida, and Taiwan).
Spix Reiseatlas original 75 (1823) by Johann Baptist von Spix, Carl Friedrich Philipp von MartiusOriginal Source: Wikimedia Commons
Artistic representations
In the third volume of the book ‘Travels in Brazil’ (1831), the botanist von Martius presented one of the first artistic representations of the species. The central tree is an adult individual Bertholletia excelsa, with fruits, vines, and many epiphytes.
Its flowers are large, robust, and fleshy. The male part has a structure not found in any other plant family. The fertile stamens are arranged around the ovary in a ring, which expands to one side forming a “hood”.
Brazil nut flowers by Scott Alan MoriOriginal Source: The Lecythidaceae Pages
The protective hood
At the apex of this “hood” are numerous yellow, nectar-producing appendages. The apex of the “hood” presses against the entrance to the ovary and the six petals of the flower form an overlapping “cup” that blocks the entrance of the flower to all insects except its pollinators.
Pollination: the strength of bees
The flower of the Brazil nut tree can only be pollinated by bees strong enough to lift the flower’s “hood”, with a tongue long enough to pass through the flower’s complex spiral. As they seek more nectar, the bees carry pollen from one tree to another.
The fruits of the Brazil nut tree
The fruits are round and woody, the size of a cannonball. When ripe, they fall to the ground with 10 to 25 edible seeds trapped inside.
The rodents’ turn
The walls of the fruit are gnawed by agoutis (rodents the size of a cat) and squirrels, which eat some seeds and store others for future consumption. Some of the stored seeds are forgotten and eventually germinate to form the next generation of trees.
Valuable seeds
The seeds are also highly valued by humans. They are consumed raw, roasted or in the form of flours, sweets, and ice cream. In addition, the oil extracted from the seeds has great nutritional and medicinal value. It is also widely used for making cosmetics.
Mulher carregando saco de castanha (2019) by Cleber Oliveira de AraújoMemorial dos Povos Indígenas
Sustainable use
The Brazil nut is the main non-timber product of the Amazon. Exports between January and July 2021 earned Brazil $21 million. It is harvested in a highly sustainable way, showing that it is possible for humans to live well and make money without cutting down the forest.
Amazon Road (1971) by John DominisLIFE Photo Collection
Not always sustainable
However, some studies have shown that continuous and uncontrolled harvesting of Brazil nuts for long periods may result in Brazil nut groves without young trees, and thus no replacement when the older trees die.
Aerial image of a forest with Brazil nut trees (August 09, 2018) by Instituto Centro VidaOriginal Source: ONF Brasil
Humans and tropical forests
We continue to learn that tropical forests are so complex that every time they are exploited by humans, this causes negative impacts on their ecology and diversity. The Brazil nut trade can contribute to the preservation of the forest, but only if it is practiced consciously.
Research and writing: Fernando B. Matos (CRIA)
Assembly: Fernando B. Matos (CRIA)
Review: Luiza F. A. de Paula (UFMG/CRIA); Renato De Giovanni (CRIA)
References: Flora Brasiliensis (http://florabrasiliensis.cria.org.br/opus); Travels in Brazil (https://www2.senado.leg.br/bdsf/handle/id/573991); The Lecythidaceae pages (https://sweetgum.nybg.org/science/projects/lp/)
Additional information: http://florabrasiliensis.cria.org.br/stories
Acknowledgments: To the authors of the photos, Instituto Centro Vida, and Dr. Scott A. Mori (1941-2020), researcher at the New York Botanical Garden, specialist in the Lecythidaceae family and curator of the "The Lecythidaceae pages".
*Every effort has been made to credit the images, audio, and video and correctly recount the episodes narrated in the exhibitions. If you find errors and/or omissions, please email contato@cria.org.br
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