You're visiting the island of Sumatra. The local people describe a plant, with a ten-foot flower resembling a giant male member, that emits the almost unbearable stench of rotting flesh. Your party searches the jungle high and low, but finds nothing. You leave wondering if indeed it's fact or fiction.
Fans of exotic plants know just such a flower exists. The amorphophallus titanum is the largest flower (or inflourescence) in the world. The flower only blooms for a few days, stinks like rotting meat to attract flies for pollination, then rests for several years before blooming again. (no wonder you couldn't find it!)
Before I got bitten by the "tropical plant bug" a few years ago, I didn't realize that new species of plants are being discovered almost every day. I'm not talking about hybrids (either natural or man-made), or slight genetic variations or varieties, I mean previously unknown plants discovered in the wild.
So far, no one has discovered a plant that can detect man's presence and run away and hide. Plants, unlike animals, tend to stay put. If we haven't found all the immobile plant species, is it naive to assume we've found all the animals that can actually hide from us?