Woolly Cup Grass - Eriochloa villosa (Thunb.) Kunth

Woolly cupgrass inflorescence
Figure 1: Woolly cupgrass inflorescence

Woolly cup grass (Eriochloa villosa (Thunb.) Kunth) is an invasive plant that can compete with crops, especially corn and soybean, and reduces crop yield.  It has become well established in the midwest United States where it is an economic concern for corn and soybean farmers. It is more challenging to control than other annual grasses. Targeted herbicide applications may be required to keep the weed in check.

Key Points:

  • A tall, annual grass native to Asia
  • Affects corn and soybean crops
  • Difficult to control
  • Spreads with farm equipment, seed and grain
  • Prohibited in seed under the Seeds Act

 

Where it's found

Woolly cup grass grows in cultivated fields, pastures and disturbed areas along fences, ditches and roadsides.

Woolly cup grass is native to Asia and was introduced to the U.S. around the 1950s. In Canada, it has been reported in a number of sites in Quebec, where a number of measures have been taken to prevent its spread.

What it looks like

To the untrained eye, this invasive plant can look a lot like common grasses that grow in Canada.

Woolly cup grass gets its name from the hair that covers many parts of the plant. It is a tall (1-2 m) annual grass with dark green and densely hairy leaves that have a velvety feel. Only one edge of the leaf blade is typically crinkled and the flowering branches are also one-sided.

How it spreads

Woolly cup grass seed commonly spreads with farm equipment and as a contaminant of seed and grain of corn, soybean and other cereals such as millet and sorghum.

Legislation

Woolly cup grass is listed as a prohibited noxious weed in the Weed Seeds Order under the Seeds Act. Its presence in domestic and imported seed for planting is prohibited.

What we can do about it

There are steps you can take to help stop the spread of this weed in Canada:

  • Use certified seed.
  • Ensure machinery brought onto the farm or to other areas is free of soil and plant parts.
  • Look for woolly cup grass in crops and in disturbed areas.

Reporting this invasive plant should be done through your local CFIA office. For a list of offices please call 1-800-442-2342 or visit the the CFIA website at: www.inspection.gc.ca.

Click on image for larger view

Woolly cupgrass infesting the edge of a corn field
Figure 2: Woolly cupgrass infesting the edge of a corn field

Woolly cupgrass inflorescence branch
Figure 3: Woolly cupgrass inflorescence branch

Woolly cupgrass seedling
Figure 4: Woolly cupgrass seedling

Woolly cupgrass
Figure 5: Woolly cupgrass

 

Photo Credits

Figure 1: Woolly cupgrass inflorescence
Photo: Anna Gardner@Iowa University 2000

Figure 2: Woolly cupgrass infesting the edge of a corn field
Photo: Mylène Bourgeois, CFIA

Figure 3: Woolly cupgrass inflorescence branch
Photo: Romain Néron, MAPAQ

Figure 4: Woolly cupgrass seedling
Photo: Romain Néron, MAPAQ

Figure 5: Woolly cupgrass
Photo: Romain Néron, MAPAQ

Invasive plants are plant species that spread when introduced outside of their natural past or present distribution and cause serious and often irreversible damage to Canada’s ecosystems, economy and society.