Brazil nut

For some reason, this topic fascinates me, as I finish the last handful of Brazil nuts in the house.

Brazil nuts only produce fruit in virgin forests (forests not previously disturbed by human activity), as forests that are not virgin usually lack an orchid that is indirectly responsible for the pollination of the flowers. The Brazil nut tree's yellow flowers can only be pollinated by an insect strong enough to lift the coiled hood on the flower and with tongues long enough to negotiate the complex coiled flower. The orchids produce a scent that attracts small male long-tongued orchid bees (Euglossa spp), as the male bees need that scent to attract females. The large female long-tongued orchid bee pollinates the Brazil nut tree. Without the orchid, the bees cannot mate, and therefore the lack of bees means the fruit do not get pollinated.

If both the orchids and the bees are present, the fruit takes 14 months to mature after pollination of the flowers, and is a large capsule 10–15 cm diameter resembling a coconut endocarp in size and weighing up to 2 kg. It has a hard, woody shell 8–12 mm thick, and inside contains 8–24 triangular seeds 4–5 cm long (Brazil nuts) packed like the segments of an orange; it is not a true nut in the botanical sense.

The capsule contains a small hole at one end, which enables large rodents like the Agouti to gnaw open the capsule. They then eat some of the nuts inside while burying others for later use; some of these are able to germinate to produce new Brazil nut trees. Most of the seeds are "planted" by the Agoutis in shady places, and the young saplings may have to wait years, in a state of dormancy, for a tree to fall and sunlight to reach it. It is not until then that it starts growing again. Capuchin monkeys have been reported to open Brazil nuts using a stone as an anvil.

Despite their name, the most significant exporter of Brazil nuts is not Brazil but Bolivia, where they are called almendras. In Brazil these nuts are called castanhas-do-Pará (literally "chestnuts from Pará"), but Acreans call them castanhas-do-Acre instead. Indigenous names include juvia in the Orinoco area, and sapucaia in Brazil.
[snip]
Brazil nuts contain small amounts of radium, a radioactive material. Although the amount is very small, about 1–7 pCi/g (40–260 Bq/kg), and most of it is not retained by the body, this is 1000 times higher than in other foods. According to Oak Ridge Associated Universities, this is not because of elevated levels of radium in the soil, but due to "the very extensive root system of the tree.

[From Brazil nut - Wikipedia, the free encyclopedia which has pictures]

Apparently, classified as vulnerable, so I guess I shouldn't eat thousands at a time.