Rhubarb is a plant with large green leaves and thick, crisp stalks that are usually bright red or pink. The stalks have a sharp, sour taste that makes your mouth pucker, but when cooked with sugar, they become sweet and delicious in pies, jams, and desserts.

Though rhubarb tastes like a fruit and gets used like one in cooking, it's actually a vegetable. The stalks are the only part you can eat: the leaves contain chemicals that can make people sick, so they always get cut off and thrown away.

Rhubarb grows well in cool climates and appears in gardens each spring, which is why people sometimes call it “pie plant.” If you've ever had strawberry-rhubarb pie, you know how that sour tang balances perfectly with sweet strawberries.

The word “rhubarb” also has a curious second meaning in theater and film. When actors need to create the sound of background conversation or a crowd murmuring, directors sometimes tell them to repeat the word rhubarb, rhubarb, rhubarb over and over. The repeated syllables create a convincing mumble of indistinct voices without anyone actually having to make up real conversations.