Oryza

Oryza is a genus of seven to twenty species of grasses in the tribe Oryzeae, within the subfamily Bambusoideae, native to tropical and subtropical regions of Asia, Northern Australia and Africa. The genus includes the major food crop species Oryza sativa. Members of the genus grow as tall, wetland grasses, growing to 1–2 m tall; the genus includes both annual and perennial species.

Oryza is situated within the tribe Oryzeae, which is characterized morphologically by its single-flowered spikelets whose glumes are almost completely suppressed. In Oryza, two sterile lemma simulate glumes. The tribe Oryzeae is within the subfamily Bambusoideae, a group of Poaceae tribes with certain features of internal leaf anatomy in common. The most distinctive leaf characteristics of this subfamily are the arm cells and fusoid cells found in their leaves. The Bambusoideae are in the family Poaceae, as they all have fibrous root systems, cylindrical stems, sheathing leaves with parallel-veined blades, and inflorescences with spikelets.

While USDA plants lists have only seven species, others have identified up to 17, including O. sativa, O. barthii, O. glaberrima, O. meridionalis, O. nivara, O. rufipogon, O. punctata, O. latifolia, O. alta, O. grandiglumis, O. eichingeri, O. officinalis, O. rhisomatis, O. minuta, O. australiensis, O. granulata, O. meyeriana, and O. brachyantha. One species, Asian rice (O. sativa), provides 20% of global grain and is a food crop of major global importance. The species are divided into two subgroups within the genus.

Selected species

• Oryza australiensis
• Oryza barthii
• Oryza glaberrima - African rice
• Oryza latifolia
• Oryza longistaminata
• Oryza meridionalis
• Oryza officinalis
• Oryza punctata
• Oryza rufipogon - brownbeard or red rice
• Oryza sativa - Asian rice
• Oryza nivara - Indian wild rice