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Weed Seed: Eriochloa villosa (Woolly cup grass)

Invasive Plant - Woolly cup grass (Eriochloa villosa)



Common name

Woolly cup grass


Prohibited Noxious, Class 1 in the Canadian Weed Seeds Order, 2016 under the Seeds Act. All imported and domestic seed must be free of Prohibited Noxious weed seeds.

Listed on the List of Pests Regulated by Canada established under the Plant Protection Act.


Canadian: Limited populations are under official control in QC.

Worldwide: Native to temperate and subtropical parts of eastern Asia. Reported to be introduced beyond its native range in the Caucasus region, western Siberia, southern Asia and Iran. Also introduced to the Ukraine, France and the United States (Darbyshire et al. 2003Footnote 1). Well-established in the mid-western states (CFIA 2014Footnote 2).

Duration of life cycle


Seed or fruit type


Identification features



Surface texture


Other features

Habitat and crop association

Cultivated fields, open grassy places, hillsides, roadsides, along fences and ditches, and wastelands (CFIA 2012Footnote 3, 2014Footnote 2). A problematic weed in corn and soybeans in the United States (CFIA 2014Footnote 2).

General information

Woolly cup grass was accidentally introduced into the United States in the 1940s (Owen 1990Footnote 4). In the midwestern United States, where it interferes with corn and soybean crops, it has proven difficult to control with pre-emergence herbicides because it germinates throughout the growing season (Owen 1990Footnote 4).

This species has also appeared in climatic zones outside of the Midwest in places such as California and Pennsylvania, suggesting that the species can adapt to many climatic conditions (Darbyshire et al. 2003Footnote 1).

Similar species

Field paspalum (Paspalum laeve)


Woolly cupgrass (Eriochloa villosa) spikelets, florets and caryopses
Woolly cupgrass (Eriochloa villosa) spikelet
Woolly cupgrass (Eriochloa villosa) spikelet, side view
Woolly cupgrass (Eriochloa villosa) spikelet base with ring of hardened tissue
Woolly cupgrass (Eriochloa villosa) floret with inner bracts
Woolly cupgrass (Eriochloa villosa) caryopsis

Similar species

Similar species: Field paspalum (Paspalum laeve) spikelet
Similar species: Field paspalum (Paspalum laeve) floret, profile
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