Rottboellia cochinchinensis

Rottboellia cochinchinensis is a species of grass known by the common names Itchgrass, Raoul grass, corngrass, Kokoma grass, Guinea-fowl grass, jointed grass, Shamwa grass and Kelly grass. It is a tall, tufted annual grass whose stems (culms) grow up to 3 metres (9 ft 10 in) in height with leaf-blades of up to 45 centimetres (1 ft 6 in) in length. The species flowers at the apex of culms in the form of spike-like racemes composed of paired spikelets. The common name Itchgrass comes from the bristly (hispid) leaf-sheath which can be irritating to the skin.

Rottboellia cochinchinensis is native to tropical Asia and Africa and has also been introduced to the Americas where it is often considered to be an invasive species. It is a major weed of a wide range of crops including maize, rice, sorghum and sugar cane.