Cotton plants grow via a series of nodes developing up the main stem, with branches beginning to form after the fifth or sixth node. Along the branch, buds grow, often referred to as cotton "squares," says the Cooperative Extension System, a network of 74 U.S. universities and their local extension services.
The University of Missouri Extension Service reports that squares mature for about three weeks before the flowering process begins. Eventually, these flowers give way to bolls, the rounded sac of seeds that holds the lint fibers associated with the plant. At this stage, productivity of the plant may be injured should the cotton plant's primary nemesis -- the boll weevil -- infest the boll.
Commercial growers have altered cotton's original lifespan. "Whereas by nature the plant is a perennial tree (lasting about 10 years), under extensive cultivation it is mostly grown as an annual shrub," says the United Nations Conference on Trade and Development. The height of the domesticated version ranges between 4 and 7 feet.