Avocados

Avocados are toxic to almost all animals (including cats and dogs). Humans are a rare exception. It is the only fruit to contain persin, a fatty acid which, when eaten by animals, causes vomiting, diarrhoea, and other nasty symptoms. Consumption of large quantities can cause death within twelve hours. Avocados are berries (fleshy fruits coming from a single ovary). Interestingly, this broad definition of a berry means that bananas, pumpkin, tomatoes, watermelon, and coffee are also berries (you can tell that to the next person who tries to argue that tomatoes are vegetables). Curiously, this also excludes strawberries as berries. Eighty percent of modern avocados originate from one 'mother' tree which was patented by Mailman Rudolph Hass from California in 1935. The tree survived until 2002 when it died of root rot. Unfortunately, Hass only made $5,000 in his lifetime from his patent on the tree because his partner sold cultivars to anyone who wanted to buy them. Subsequently, Hass spent the remainder of his life working for the California Mail Service. Avocado also has an interesting characteristic: it is the only berry with no living animal large enough to spread it through consumption and release as dung.