Why does a pineapple have thorns?

It's worth remembering that pineapples are not a natural fruit but a cultivated one; the wild varieties are much smaller and less luscious. I don't know the answer to the question, but I'd speculate a couple of possibilities. read more

The "thorns" on the pineapple are actually the wilted petals of the flowers from which the fruit is born. There's no real reason for them except that the flowers did, at one point, serve a purpose and when they died they remained attached to the skin. read more

The skin of the pineapple plant is not considered poisonous, and while the entire fruit is considered non-toxic, the unripe flesh, thorns and leaves can have toxic effects. This is due to the enzyme bromelain, which is used as a meat tenderizer and is considered very low in toxicity. read more