Ricegrass, Paspalum scrobiculatum, is a tufted perennial grass growing from 47-59 in. (120-150 cm) tall. It has a decumbent ascending culm and can root at the nodes. The erect culms are stout and glabrous.

Foliage

The flat lanceolate leaf blade is from 4.7-15.8 in. (12-40 cm) long and from 0.12-0.47 in. (3-12 mm) wide with a whitish margin. There is a dense row of hairs behind the short ligule.

Flowers

The inflorescence has three to four racemes up to 19.3 in. (49 cm) long. Racemes are held on a simple unbranched axis.

Fruit

Seeds are about 0.08 in. (2 mm) long x 0.06 in. (1.5 mm) wide.

Ecological Threat

P. scrobiculatum typically occurs in wetlands and is often associated with disturbance such as urban areas, agricultural areas, grasslands, roadsides, ditches, waste ground, and rice fields. It can form extensive populations.

Citations

Rawlins, K.A., R.L. Winston, C.T. Bargeron, D.J. Moorhead, and R. Carroll. 2018. New Invaders of the Southeast. USDA Forest Service, Forest Health Assessment and Applied Sciences Team, Morgantown, West Virginia. FHTET-2017-05. Retrieved from http://bugwoodcloud.org/resource/pdf/FHTET-2017-05_New%20Invaders_SE.pdf

 

Resources

• Federal Noxious Weed Disseminules of the U.S. - USDA-APHIS

Selected Images

Maps

Invasive Listing Sources

• Federal Noxious Weeds
• Florida Noxious Weeds
• Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
• Massachusetts Noxious Weeds
• Massachusetts Prohibited Plant List
• New Invaders of the Southeast
• Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
• South Carolina Plant Pest List
• USDA APHIS Regulated Pest List
• WeedUS - Database of Plants Invading Natural Areas in the United States

References