Cashew update!

Photo by Vic Lic

FLASH! There’s an urgent addendum to my previous post about the stupendous Blister Nut.

You may recall that the cashew is unique in a variety of ways. Here are some of those ways, as a refresher. (Pay attention for god’s sake!)

• There is only one nut per cashew fruit (also known as the apple) and it is outside the fruit.
• The nut itself is surrounded by a highly caustic oil that causes a rash when touched.
• The one-nut-per-fruit and dangerous nature of the cashew is what causes its price to be higher than other nuts.

This week I was with a colleague who served in the Peace Corps years ago as a farmer planting, yes, cashew trees in Ghana. Score! Here is what I learned.

The skin of the fruit is not caustic like the nut. In fact, many people use the fruit, which is high in sugar, to ferment into booze. (Seems like I have next year’s boutique homebrew!)

But there’s more. The skin around the nut is not caustic either (which I misunderstood initially). It is the oil inside the skin, between it and the nut, which is harmful. Thus animals are attracted to the fruit — mmm, juicy — and end up eating the nut too. The skin does not digest and the nut passes intact out of the animal with the rest of the poop. And here is the evolutionary awesomeness: the poop is almost certainly at some distance from the place of ingestion, thus ensuring wider and wider propagation of the cashew seed. Not unlike the way pollen spreads through the external agency of birds and bees.

Isn’t that fascinating?