Weed Seed: Bothriochloa laguroides (Silver beardgrass)
Canadian: Absent from Canada (Brouillet et al. 2016Footnote 1)
Worldwide: Native to North and South America, from the central United States to Argentina and Chile (USDA-ARS 2016Footnote 2).
Duration of life cycle
Seed or fruit type
- Spikelet length: 3.5 - 4.0 mm
- Spikelet width: 1.5 - 1.7 mm
- Awn length: up to 12.0 mm
- Spikelet is long oval shape with 2 pedicels from the base
- Spikelet is smooth and shiny with white hairs
- Spikelet is pale yellow
- A pair of pedicels extend ¾ up the ventral side of the spikelet.
- Pedicels may have sterile spikelets attached.
- Copious white hairs around the base of and along the margins of the spikelet and the pedicels.
- Short teeth along the upper margins of the dorsal side of the spikelet.
Habitat and Crop Association
Field edges, pastures, grasslands, woodlands, river bottoms, and roadsides, on well-drained soils and often on limestone (Barkworth et al. 2003Footnote 3). Reported as a weed in alfalfa, beans and corn in Mexico (Hanan Alipi and Mondragón Pichardo 2009Footnote 4).
Silver beardgrass has been used in landscaping in the United States (Barkworth et al. 2003Footnote 3).
Yellow bluestem (Bothriochloa ischaemum)
- Yellow bluestem is a similar size, oval shape, yellow colour and smooth surface as silver beardgrass.
- Yellow bluestem spikelets on average are 4.5 mm long and 1.0 mm wide, approximately 1.0 mm longer than silver beardgrass.
- The teeth on the back of yellow bluestem bracts are larger, and the hairs at the tips of the pedicels are 3.0 mm shorter than silver beardgrass.
- The dorsal side of silver beardgrass spikelets is smooth and pale; yellow bluestem spikelets are furrowed with purple tips.
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