Resurrection ferns. Nature's opportunists. When it's dry out, they go on powersave, turn brown, and shrivel up. To the untrained eye, they look totally dead. In fact, however, they're just playing possum with precipitation. Cause when it rains, the resurrection fern perks back up and turns as verdant and fluffy as Oscar the Grouch. They're a parasite, really. In fact, if granted free reign, they'll eventually kill their host, robbing it of its nutrients and weakening its metabolic functions.
Damn, what a lovely way to go, though: Death by fern. I love resurrection ferns, and I don't mind that they're as much a menace as a decoration. (Ain't we all?) These pleopeltis polypodioides have been growing on this old oak in my parents yard for years and years, giving the old patriarch the effect of wearing bushy green shirtsleeves. But only after a rain. When it's dry out, that oak is as naked as the naked eye.