Which plant grows fastest of all?

Some bamboos put on close to a metre a day - fast enough to see, if you sit and watch. That is possible because the plant is not really building new tissue at the tip; the cells are already there, stacked in the shoot like a collapsed telescope, and growth is largely a matter of pumping them full of water and letting them elongate.

Bamboo is a grass, which is why it does this. It grows from the base of each segment rather than the tip, which is also why grass survives being mown and trees do not. A stand of it is usually one plant - a single connected root system sending up shoots - so a bamboo forest can be one organism.

The flowering is the strangest part. Many species flower gregariously: every plant of that species, everywhere in the world, flowers in the same year, sets seed, and dies - on a clock that can run to 120 years. Plants separated for a century on different continents keep time with each other. In parts of India the event is followed reliably by a plague of rats, which breed on the seed glut and then move on to the crops, and the local name for the resulting famine long predates any scientific account of it.