The world's tallest grass is bamboo. Bamboo is a flowering perennial evergreen plant in the grass family, Poaceae. Soft bamboo shoots, stems, and leaves are the major food source of the giant panda of China, the red panda of Nepal and the bamboo lemurs of Madagascar.
It's either bamboo or elephant grass.
Bamboo.
Many Species of Bamboo can grow upwards of 100 feet (30 m) The tallest I've heard of is Moso, http://www7.ocn.ne.jp/~bwc/pictureMoso01.jpg Most of the tall varieties of bamboo are members of the Phyllostachys genus http://en.wikipedia.org/wiki/Phyllostachys i'd say the tallest grass is banana
sun flower Bamboos are fastest growing plants eaten as vegetables by several communities of people
rainforests
bamboo
Its Bamboo
bamboos
grass growing is a physical change.
Bamboo, specifically giant bamboos are the tallest in the grass family.
Some of the Bamboos.
bamboo
gaint bramuda grass i think corn is the tallest
Grass started growing across the the world.