The oaks have waxy, cup-shaped leaves — not only do they rarely go up in flame, but they can catch embers out of the sky and extinguish them, Yelchin said.

In particular, goblet cells -- cup-shaped cells that secrete mucus -- expressed those genes only in the presence of ILC2s, a kind of immune cell.

The plant uses a musky odor to lure fungus gnats that usually feed and lay their eggs on mushrooms into their cup-shaped flowers.

Sometimes described as appearing like a stack of deflated balloons or some dropped lasagna, the organelle called the Golgi body is composed of a series of cup-shaped membrane-covered sacs.

Her cup-shaped home is made of mud, covered in moss and cantilevered over a glass light fixture — an avian Fallingwater.