Which plant grows the fastest?

Some species of bamboo are the fastest-growing plants on Earth, with records of growth up to around 90 centimetres in just 24 hours under ideal conditions. Bamboo is actually a type of giant grass, and its rapid growth comes from special growth zones spaced along the stem that all lengthen at once. A bamboo shoot can reach its full height in a single growing season, then spend years hardening. This speed makes bamboo a valuable, renewable material for building, food, and paper. Many algae and duckweed can also multiply extremely fast, though they are much smaller.