Family: Poaceae
Cenchrus echinatus (sandbur, Mossman River grass) is a grass native to North America and South America. While it does have some medicinal uses and can serve as forage for grazing animals, it is predominantly recognized as an unwelcome weed in pastures, lawns, and disturbed areas. The grass forms spiny seed heads, posing challenges for grazing animals and diminishing forage quality. Moreover, its seeds feature a hard, sharp outer casing, causing disruptions in agriculture and provoking irritation to both animals and humans. Widely naturalized globally, it has been reported on Kure and Midway atolls, Lisianski, Laysan, French Frigate Shoals, Nihoa, and all the main Hawaiian islands. Known for its rapid establishment and spread, along with the sharp seed heads, it earns its reputation as a problematic weed, creating difficulties in both agricultural and natural ecosystems. Furthermore, this grass has the potential to impact native coastal vegetation and seabird habitat.
High Risk Traits:
- Thrives, and spreads, in regions with tropical climates
- Naturalized on Kure and Midway atolls, Lisianski, Laysan, French Frigate Shoals, Nihoa, and all the main islands; naturalized elsewhere
- A disturbance-adapted grass that impacts lawns and several crops
- An environmental weed impacting native coastal vegetation and seabird habitat
- Other Cenchrus species are invasive weeds
- Possesses spiny burrs that contaminate wool, and can injure the eyes, tongue and feet of dogs and stock, including horses; also harmful and a nuisance to humans
- May be allelopathic
- Reproduces by prolific seed production
- An annual grass reaching maturity in <1 year
- Seeds easily dispersed by adhering to clothing, hair, and feathers, as well as footwear and machinery, and also dispersed by water
- Seeds may form a seed bank persisting for 1-5 years
- Tolerates mowing and grazing
Low Risk Traits:
- Palatable to, and grazed by livestock, especially when young
- Occurs primarily in sandy soils
- Thrives in high light environments (dense shade may prevent establishment and spread)
- Vegetative spread may be minimal and very localized
- Herbicides provide effective control
