What are these things growing on our red potato plants?

That, believe it or not, is the actual fruit of the potato plant

Don’t eat them, though; they’re toxic

Harp, you may have just saved some lives, today. I’m not joking.

You should be very proud. I know I am..

shucks

Those are OK, actually, but the ears of the corn are more enjoyable to eat.

sucks

Hmmm…I wonder why nature thought it’d be a good idea
to put something toxic next to something so tasty?

To keep animals from eating it?
Then why make it so tasty in the first place?
And what keeps the toxicity from spreading?

Potatoes, like tomatoes, eggplants, tobacco and petunias, are members of the Nightshade family. A characteristic of these plants is that they produce alkaloids, chemical compounds that are extremely toxic in some forms, benign or medicinal in other forms. The nicotine in tobacco is a non-toxic alkaloid.

The alkaloids are concentrated in different parts of the plant in different species. The In potatoes, the tubers are relatively free of the toxins, except when the tubers turn green in reponse to light and begin to sprout (that’s why it’s always recommended to trim away green patches and sprouts on a potato before cooking). The foliage of tomato plants is high in toxins, but the fruits get spared.