Oryza rufipogon

Oryza rufipogon, common wild rice or brownbeard rice, is a perennial aquatic grass of the family Poaceae considered to be the wild progenitor of cultivated Asian rice (Oryza sativa), with which it shares the AA genome. The slender, semi-floating culms reach up to about 2 m in length, often rooting at the lower nodes and producing long, narrow, ribbon-like leaves with rough margins. The inflorescence is a loose to somewhat compact terminal panicle bearing large spikelets 6-10 mm long, each typically tipped with a strong straw-coloured to reddish awn 4-10 cm in length that is a key distinguishing feature from domesticated rice. The grains shatter readily at maturity and germinate in shallow water. Native to seasonal swamps, pond margins, ditches, and rice-field edges across East, Southeast, and South Asia, it is regarded as a noxious weed of paddy fields in some regions.