They don't need water to survive and bring at least as much joy as real flowers.
Stil means style and blüte is a blossom. Yet a Stilblüte is not a special kind of flower, but rather a stylistic blunder. It can be unintentionally funny and typically blooms in sentences having a double meaning, or when someone uses the wrong word.
Try to spot the Stilblüte in these two sentences:
Leider bekomme ich keine Katze, weil meine Mutter einen Vogel hat.
It literally translates as "Unfortunately I won't be getting a cat, because my mother has a bird." But "einen Vogel haben," ie. "to have a bird" is also a German expression which means to be crazy.
Wenn man kurzsichtig ist, geht man zum Optimisten.
Translation: "Shortsighted people need to visit the optimist." If you haven't lost your glasses, you probably noticed the word which should have been used here is optometrist.
Got any to share?