A running bamboo is botanically classed as a “monopodial” species. It is usually a temperate zone originator characterised by the development of an open network of horizontal underground stems called rhizomes, from which the new culms grow.
This invasive habit has earned this group the name of “running” bamboo. The picture below displays the rhizome form which gives the bamboos belonging to the monopodial group it’s fantastic yield in commercial farming, and it’s mythical lack of controllability.