Book 30, Question 65
What is duckweed, and why does it grow so fast?
Duckweed is a tiny floating plant, often only a few millimeters wide, with a leaf and a thread-like root.
It's one of the smallest flowering plants. It grows by budding, making copies of itself, and can cover a pond in a green carpet in weeks when it's warm and full of nutrients. Ducks and fish nibble it. A thick mat can block light.