There are over 1,000 different species of bamboo classified into 91 genera. They are generally split into two different types based on how their rhizomes tend to grow: running bamboo and clumping bamboo. The former tends to grow in more temperate climates, features rhizomes that grow horizontally, and spreads quickly; the latter is more common in tropical areas, has shorter, thicker rhizomes that spread more slowly, and doesn’t take up as much space.