the PRICKLY COTTON-TREE, in botany, a genus of the polyandra monogynia clasps of plants, the corolla whereof consists of a single petal, divided into five oval, hollow, patent segments: the fruit is a large, oblong, turbinated capsule, formed of five woody valves, and containing five cells; the seeds are roundish, and fixed to a columnar pentagonal receptacle, and have a quantity of fine down, or cotton, adhering to them.