Bamboo

Bamboo can grow bigger than most trees and has a very hard outer layer yet it is in the Poaceae family; it is a type of grass. It is related to the grass that grows on lawns. 

Image generated by AI (wonder) 

Some species of Bamboo have been known to grow over 90cm in one day. They're the fastest growing plant in the world. Bamboo is also one of the most useful plants in the world, it has a wood like stem and the plant fibers can be used to make different papers, toilet paper, packaging and things like that. 

Source : Wikipedia