FlowerBot is a very nicely implemented robotic flower developed for Carnegie Mellon University's TeRK project. FLowerBot can track objects moving nearby; it can even grab or bite down on anything that comes close enough.
Take a look at this brief FlowerBot video.
I can't recall an exact match to FlowerBot in sf. However, in his 1964 novel The Killing Machine, Jack Vance refers to a flexible robotic stem used in religious festivals; a person wearing flower petal robes performs at the tip.
I learned that the stems are built up of several dozen smaller tubes, each containing a magnetic slurry: iron powder in a viscous liquid. Reacting to fields from internal windings, these tubes selectively contract with great force. By proper circuitry any contortion of the tubes is posible.
Scroll down for more stories in the same category. (Story submitted 10/18/2008)