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. They are 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 character of this subfamily is their arm cells and fusoid cells found in their leafs. 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 only 7 species, others have identified up to 17, including sativa, barthii, glaberrima, meridionalis, nivara, rufipogon, punctata, latifolia, alta, grandiglumis, eichingeri, officinalis, rhisomatis, minuta, australiensis, granulata, meyeriana, and brachyantha. One species, Rice (O. sativa), provides twenty percent of global grain and is a food crop of major global importance. The many species mentioned above are divided into two subgroups within the genus
Full article ▸