Oryza

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Oryza
Gealypic5.JPG
Oryza sativa
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
(unranked): Commelinids
Order: Poales
Family: Poaceae
Subfamily: Ehrhartoideae[1]
Tribe: Oryzeae[1]
Genus: Oryza
L.
Species

See text.

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[2] and Africa. The genus includes the major food crop rice species Oryza sativa and Oryza glaberrima. 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.[3]

While the United States Department of Agriculture has a plants list with only seven species of Oryza, 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.[citation needed] 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

References[edit]

  1. ^ a b Kellogg, Elizabeth A. (30 January 2009). "The Evolutionary History of Ehrhartoideae, Oryzeae, and Oryza". Rice 2: 1–14. doi:10.1007/s12284-009-9022-2. Retrieved 6 July 2013. 
  2. ^ Abbie Thomas Native rice may hold key to food future 15 October 2010 http://www.abc.net.au/science/articles/2010/10/15/3038568.htm?topic=
  3. ^ Heywood, V.H. Flowering Plants of the World 1993 Oxford University Press