Think of the delicious sweet aroma that comes from marzipan, or Amaretto liqueur, or anything with a touch of almond extract. That scent comes from benzaldehyde. It is a part of nature's underhanded scheme to destroy mankind, although the plants that produce it would tell you it's just a defense mechanism so they can reproduce successfully.
Some plants produce amygdalin in their fruit pits. When that chemical is released by crushing or chewing, the amygdalin breaks down into two chemicals: the benzaldehyde that smells so good, and cyanide. The way these plants evolved, any creature that eats it is supposed to learn to stay away when they encounter that smell -or else just die. However, humans love it. Amygdalin is present in the seeds of peaches, apricots, cherries, mamey sapote fruit, cassava, and most of all, almonds.
But don't let that keep you from eating those foods. Cultivation of almond trees has given us the sweet almond, which has way less cyanide than natural bitter almonds, and people have learned to process the other foods to reduce their toxicity. You have to wonder how many people were killed on the way to learning those methods. Read about the cyanide in natural fruits and nuts at Atlas Obscura.
(Image credit: Ivar Leidus)