itchgrass

Family

Poaceae

Scientific Name

Rottboellia cochinchinensis

Other Common Names:

corngrass

raoulgrass

Synonyms (former Scientific Names):

Rottboellia exaltata

Aegilops exaltata

Manisuris 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.

Leaf Hair on Upper Surface

hairs from base to tip

Leaf Arrangement

rolled in bud

Mature Leaf Width

Varies:

less than 5 mm,

6 to 15 mm,

more than 15 mm

Stem

flat or oval

Seedhead

spike

Root Structure

fibrous

Life Cycle

summer annual

Auricle

not present

Ligule

Varies:

membrane,

hairy

Ligule Length

Varies:

less than 1 mm,

1-2 mm,

2-3 mm

Plant Type

Grass