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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."

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.

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.

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