Scientific Name: Rottboellia cochinchinensis

Common Name: itchgrass

Other Common Names: corngrass, raoulgrass

Synonyms: Aegilops exaltata, Manisuris exaltata, Rottboellia exaltata

Habit: This weed is an upright grass that can reach approximately 9 feet tall.

Leaves: The leaves of Itchgrass are approximately 4 to 20 inches long and 1.5 to 7.5 inches wide. The leaves have stiff hairs on both sides of the leaves. The ligule is hairy and around a tenth of an inch long.

Identifying Characteristics: Itchgrass can be identified by its long, stiff hairs on the sheath, presence of prop roots, roots used for support, and seed heads that are cylindrical and jointed.

Flower Seed Head: The seedhead is a raceme that is cylindrical and jointed. It ranges from 2 to 6 inches in length.

Seed Fruit: The seed is a tan caryopsis, a dry singular fruit, that breaks apart with the rachis.

Where Found: Itchgrass is mainly a weed of pastures and roadsides. It is also listed as a Federal Noxious Weed.

  • Life cycle: summer annual

  • Plant type: Grass

  • Auricle: not present

  • Plant family: Poaceae

  • Leaf arrangement: rolled in bud

  • Hair surface: hairs from base to tip

  • Ligule: hairy; membrane

  • Length: 1-2 mm; 2-3 mm; less than 1 mm

  • Root structure: fibrous

  • Seed head: spike

  • Width: 6 to 15 mm; more than 15 mm; less than 5 mm

  • Grass stem: flat or oval