There are several species of the cotton plant; but those of commercial importance are four in number. Herbaceous Cotton ('Gossypium herbaceum') is the plant which yields the East Indian 'Surat' and some varieties of the Egyptian cotton. Its habitats are India, China, Arabia, Egypt, and Asia Minor. It is an annual: it grows to a height of five or six feet, it has a yellow flower, and it yields a short staple. Tree Cotton ('Gossypium arboreum'), on the other hand, grows to a height of fifteen or twenty feet, has a red flower, and yields a fine silky wool. Its habitats are Egypt, Arabia, India, and China. Hairy Cotton ('Gossypium hirsutum') is a shrub of some six or seven feet high, with a white or straw-coloured flower, and hairy pods, which yield the staple known as American 'Upland' and 'Orleans' cotton. Another variety, called 'Gossypium Barbadense,' because it was first found in Barbadoes, grows to a height of about fifteen feet, and has a yellow flower, yielding a long staple, and fine silky wool known as 'Sea Island' cotton. This now grows most extensively on the coasts of Georgia and Florida; but has been experimented with in various parts of the world, notably in Egypt, where it has succeeded; and in the Polynesian islands, where, for some reason or another, it has failed.
The cotton plant of the American cotton plantations is an annual, which shoots above ground in about a fortnight after sowing, and which, as it grows, throws out flower-stalks, at the end of each of which develops a pod with fringed calyces. From this pod emerges a flower which, in some of the American varieties of the general species, will change its colour from day to day. The complete bloom flourishes for only twenty-four hours, at the end of which time the flower twists itself off, leaving a pod or boll, which grows to the size of a large filbert, browns and hardens like a nut, and then bursts, revealing the fibre or wool encased in three or four (according to the variety) cells within. This fibre or wool is the covering of the seeds, and in each cell will be as many separate fleeces as seeds, yet apparently forming one fleece.
Upon the characteristics of this fleece depends the commercial value of the fibre. The essential qualities of good and mature cotton are thus enumerated by an expert: 'Length of fibre; smallness or fineness in diameter; evenness and smoothness; elasticity; tensile strength and colour; hollowness or tube-like construction; natural twist; corrugated edges; and moisture.' The fibre of Indian cotton is only about five-eighths of an inch long; that of Sea Island about two inches. Then Sea Island cotton is a sort of creamy-white colour; and some kinds of American and Egyptian cotton are not white at all, but golden in hue; while other kinds, again, are snow-white.