棉花为一年生草本或多年生亚灌木或小乔木。棉花起源于热带和亚热带,原分布区域的界限与最冷月平均气温18℃的等温线相当。经长期的引种驯化,以及育种和栽培技术的发展,种植范围不断扩大,目前的产棉区分布于南纬35°到北纬48°的广大地区。但主要产棉国多在温带地区。 Cotton is an annual herb or perennial subshrub or small tree. Cotton originated in the tropics and subtropics, the original distribution of the boundaries and the coldest month average temperature of 18 ℃ isotherm equivalent. After a long period of introduction and domestication, as well as breeding and cultivation techniques, the planting area has been continuously expanded. At present, the cotton producing areas are located in the vast area of ​​35 ° latitude and 48 ° north latitude. However, most of the major cotton producing countries are in temperate regions.