The cultivated rice plant is an annual grass and grows to about 1.2 metres (4 feet) in height. The leaves are long and flattened and are borne on hollow stems. The fibrous root system is often broad and spreading. The panicle, or inflorescence (flower cluster), is made up of spikelets bearing flowers that produce the fruit, or grain. Varieties differ greatly in the length, shape, and weight of the panicle and the overall productivity of a given plant.

Here are some more details about rice:

Growth

Rice plants can grow to about 4 feet (1.2 meters) tall. They require warm, moist conditions to grow, and are usually grown in paddies, which are mud beds with low banks that are flooded with 2–4 inches (5–10 centimeters) of water for most of the growing season. However, there are also varieties of rice that can tolerate deeper flooding, and upland rice can be grown without flooding in hilly or mountainous regions.

Life cycle

After germination, rice seedlings go through a critical stage that lasts about 14 days, during which they feed on the food reserves in the endosperm and produce roots. After that, they produce new leaves at a rate of one every 3–4 days.

Other types of rice

In addition to *O. sativa*, there are about 20 other species in the genus Oryza, including *O. glaberrima*, a perennial species grown in Africa, and Zizania aquatica, also known as "wild rice", which is more closely related to oats.