Brazil Nut, Paradise Nut & Cashew

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Economic Plant Photographs #1

Brazil, Paradise & Cashew Nuts

Lecythis Family (Lecythidaceae)

Large seed capsule and seeds of Brazil nut (Bertholletia excelsa), a giant tree of the Amazon rain forest of Brazil. It belongs to the lecythis family (Lecythidaceae) and is closely related to a group of South American nut trees known as monkey pots. The woody, thick-walled, indehiscent seed capsules are about the size of a large grapefruit and weigh up to five pounds, posing a serious threat to unsuspecting persons walking beneath these trees at certain times of the year. The seed capsule in this photo has been cut open to expose the woody, wedge-shaped seeds.

The Brazil nut tree (Bertholletia excelsa) is an enormous tree of the Amazon rain forest of Brazil. The trees tower 200 feet, and their spreading branches and flowers provide habitat and food for numerous forest creatures. The woody, indehiscent seed capsules are gnawed open by the agouti, a rodent roughly the size of a large guinea pig. The agouti's chisel-like incisors penetrate the Brazil nut capsule. Some seeds are eaten, but others are carried away and buried for future meals. If forgotten, these seeds can remain dormant in the soil for several years and then germinate. Although it consumes some seeds, the agouti is responsible for reseeding the forest with Brazil nuts and ensuring the next generation of trees. Inquisitive primates apparently get their hands stuck inside the woody pods when they reach inside fruits that have been partially gnawed open. This is the derivation of the common name "monkey pot."

The large seeds of Brazil nut (Bertholletia excelsa) have a thick, woody seed coat. The micropyle where the pollen tube penetrated the ovule during double fertilization is clearly visible at one end. The oily endosperm contains about 70 percent unsaturated fat.

For centuries, scientists were puzzled because Brazil nut trees tree do not produce nuts in cultivation or in recently cleared rain forest. This is one of the few economically important plants that are exclusively harvested in their natural rain forest habitat. It turns out that Brazil nut flowers require a certain species of bee for pollination. The bees in turn require a certain species of orchid to survive. Male bees must acquire the fragrance of this particular orchid in order to attract female bees. If the forest is damaged by clearcutting, the orchids disappear, along with the bees and the Brazil nuts.

In its native habitat, the huge Brazil nut tree competes with another rain forest giant, the strangler fig (Ficus species). The sticky strangler fig seeds are deposited on Brazil nut limbs in the excrement of birds, bats and monkeys. The seeds germinate high on the moist branches, sending numerous aerial roots to the ground. Like botanical boa constrictors, the serpentine roots gradually wrap around the host's limbs and trunk, crushing the bark and constricting vital phloem and cambial layers. The network of roots, resembling a tangle of writhing snakes, also fuse together (anastomose) forming a massive woody envelope or "straightjacket" encircling the host. Expansion of the host trunk as it grows in girth may accentuate the death grip and subsequent girdling process. Eventually the host tree dies of strangulation and shading, and the strangler fig stands in its place. In many cases the host tree may actually succumb from shading and root competition rather than strangulation. When strangler figs start in the ground, as in cultivation, their trunks develop from the ground upward like other "conventional" trees.

Read About Strangler Figs & Banyans

An ignited Brazil nut supported by toothpicks. The seed contains about 70% unsaturated fat, and literally burns like a candle.

See Article About The Beneficial & Toxic Effects Of Selenium

   Koller, L.D. and J.H. Exon. 1986. "The Two Faces of Selenium-Deficiency and Toxicity--Are Similar in Animals and Man." Can. J. Vet. Res. July; 50 (3): 297-306.

Paradise nut or sapucia nut (Lecythis ollaria), a member of the lecythis family (Lecythidaceae) along with the Brazil nut (Bertholletia excelsa) and cannonball tree (Couroupita guianensis). Like the Brazil nut, the woody fruit (capsule) opens by a detachable lid (upper right), exposing the large seeds. It is related to a number of nut trees in South America, generally referred to as "monkey pots." New world monkeys apparently stick their hands into these large, potlike seed capsules to extract the seeds. Paradise nuts (seeds) are rich in oil and have a pleasant taste similar to Brazil nuts. This large, spreading tree is native to the rain forests of Brazil.

See The Cauliflorous Cannonball Tree

A large monkey pot seed capsule (Lecythis ampla) from Costa Rica. The apical cap has been removed and the "pot" is filled with Brazil nut seeds (Bertholletia excelsa). According to Richard W. Spjut (A Systematic Treatment of Fruit Types, 1994), this type of woody fruit with a dehiscent apical cap or lid is called a pyxidium. I have also seen it described as a circumscissle capsule. Photographed at Huntington Botanical Garden in San Marino, California.

Sumac Family (Anacardiaceae)

Cashew tree (Anacardium occidentale). Left: A cashew "nut" attached to its swollen stalk (pedicel). The shell of the "nut" contains the poison oak allergen urushiol, and may cause dermatitis in hypersensitive people. Right: The fleshy "apple" is the swollen stalk (pedicel) to which the one-seeded "nut" is attached. Technically, the "nut" is a dry fruit called a drupe. It consists of a thin outer layer (exocarp and reduced mesocarp) surrounding a thicker, seed-bearing endocarp. Some botanists prefer not to commit themselves and call the cashew fruit a drupaceous nut. Other ingenious names devised by botanists include drupe-like and nutty drupe.

Cashew doll from Honduras. The anatomy comes from the following six different plants. Head: From the seed-bearing "nut" or endocarp of the cashew tree (Anacardium occidentale); Hat: From the fibrous interior of a gourd, possibly Luffa aegyptiaca or L. acutangula. Loofah gourds are common in Honduras, and actually hang from telephone poles; Forearms: From the hollow thorns of a Central American thorn acacia, possibly Acacia collinsii or A. cornigera; Torso: From the seed of a Mucuna vine, possibly M. urens or M. sloanei; Legs: From the seeds of Job's tears (Coix lacryma-jobi); Feet: From a species of Erythrina, often called coral beans.

A tasty nut and fleshy fruit native to tropical America. Left: Cashew tree (Anacardium occidentale). Right: Hog plum (Spondias mombin), a delicious mango relative that also belongs to the cashew family (Anacardiaceae).

See More Members Of The Sumac Family
See The WAYNE'S WORD Poison Oak Article

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