Despite their size, the bamboos are grasses, that is, they belong to the Poaceae, like the grasses in our lawns and the wheat in our fields. Unlike conventional grasses, however, their stems are woody and persist from one year to thenex, so we could describe them as being “woody grasses”.
The tallest of the bamboos, Dendrocalamus giganteus, a tropical Asian species, can reach up to 160 feet (50 meters) in height, equivalent to a 15 story building. It is also the fastest growing plant in the world, reaching up to 3 feet (90 cm) per day.
On the opposite end of the scale, the smallest bamboo, pygmy bamboo (Pleioblastus pygmaeus) doesn’t exceed 8 inches (20 cm) in height, at least when grown in full sun, and can in fact be used as a no-mow lawn. Among the most cold-resistant of all bamboos, it will grow in hardiness zones 4 to 10.
Note that the pernicious weed sometimes called Mexican bamboo, American bamboo or Quebec bamboo, Fallopia japonica, is not a bamboo at all, but belongs to a very different family, the Polygonaceae or buckwheat family. It is more correctly referred to as Japanese knotweed.