Cultivated Rice

Cultivated rice is generally considered a semi-aquatic annual grass, although in the tropics it can survive as a perennial, producing new tillers from nodes after harvest (known as ratooning). At maturity, the rice plant has a main stem and a number of tillers. Each productive tiller bears a terminal flowering head or panicle. Plant height varies by variety and environmental conditions, ranging from approximately 0.4 m to over 5 m for some floating varieties. The morphology of rice is divided into the vegetative phases (including germination, seedling, and tillering stages) and the reproductive phases (including panicle initiation and heading stages). A rice plant takes from three to six months to reach maturity, depending on the variety.

Rice is often grown in paddies or small portions of a field with raised boundaries. These portions act as shallow puddles and utilize the rice plant's tolerance to water. The water in the paddies prevents weeds from outgrowing the crop. Once the rice is well-established in the field, the water can be drained in preparation for harvest. Rice paddies have many important functions apart from being the growing areas for rice. They provide a habitat for birds such as herons and warblers, as well as for a wide range of amphibians, crabs and snakes. These creatures contribute to maintaining a healthy and sustainable ecosystem. It is also common for fish to breed in rice paddies, often among the rice plants. These fish are an important source of protein for the rice farmer and his family.

There is also floating paddy, dry paddy, and hill paddy which are grown on slopes and terraces in various Asian countries including China, the Philippines and East Malaysia.