Family: Poaceae
Cynodon plectostachyus (giant star grass, star grass) is a grass native to Chad. It is used as a pasture grass in dry tropical areas, particularly Eastern Africa and in Central and South America. It is widely naturalized throughout the tropics and subtropics, but is not documented to be naturalized on any Hawaiian Islands to date. Cynodon plectostachyus, with its wide elevation suitability, poses risks to high-elevation areas in Hawaiʻi. The potential for cyanogenic glycoside production raises concerns about livestock poisoning. Moreover, its capacity to alter fire regimes, create dense swards, and propagate swiftly through seeds and stolons emphasizes its invasive nature. Dispersal is facilitated by machinery, human activities, and intentional efforts. The grass’s tolerance to grazing and fire heightens its potential to disrupt Hawaiian ecosystems.
High Risk Traits:
- Broad elevation range (sea level to 2000 m)
- Grows and spreads in regions with tropical climates
- Naturalized throughout the tropics and subtropics (but not in the Hawaiian Islands to date)
- Identified as an aggressive, weedy grass that may become a weed in cropping systems and could interfere with woody plant regeneration in pastures
- A potential environmental weed
- Other Cynodon species have become invasive
- May produce cyanogenic glycoside at certain stages of growth, resulting in potential poisoning to livestock
- Can modify fire regime and increase fire risk
- Tolerates many soil types
- Forms dense, monospecific swards that could inhibit other vegetation
- Reproduces by seeds and vegetatively by stolons
- Seeds dispersed as a contaminant in machinery and adhered to human clothes and animal fur, and intentionally by people
- Tolerates grazing and fire
Low Risk Traits:
- Unarmed (no spines, thorns, or burrs)
- Valued as forage grass for livestock
- Relatively shade-intolerant (dense shade or cover may inhibit spread)
- Herbicides may provide effective control
