Japanese rice (Oryza sativa japonica) - short-grained, sticky. It was domesticated in the Yangtze Valley 9-6 thousand years ago, and its varieties are usually grown in dry fields (mostly submerged in Japan), in East Asia, the highlands of Southeast Asia, and the highlands of South Asia.
Indian rice (Oryza sativa indica) - long-grained, non-sticky rice. It was domesticated around the Ganges 8.5-4.5 thousand years ago. Its varieties are mainly lowland rice, grown mostly underwater throughout tropical Asia.
