Family: Poaceae
Origin, Description & Uses
Sorghum bicolor is a highly versatile grass species native to Africa and the Indian subcontinent, where it has long been cultivated as a staple grain and forage crop. It is an annual or short-lived perennial grass that thrives in warm, seasonally dry tropical and subtropical climates. The plant produces tall, cane-like stems topped with dense seed heads, and is widely grown for a variety of uses including human food (grain, flour, and syrup), livestock fodder, biofuel production, and erosion control. Its drought tolerance and adaptability have made it an important crop in both subsistence and commercial agriculture around the world, including in tropical island settings.
Risks & Threats
In Hawaiʻi, Sorghum bicolor is naturalized on Kauaʻi, Oʻahu, and Hawaiʻi Island, where it can persist in disturbed areas such as roadsides, agricultural lands, and abandoned fields. While it is generally considered a low-risk species due to its agricultural value and limited tendency to aggressively invade intact native ecosystems, it can still establish outside cultivation and contribute to vegetation in disturbed habitats. Its presence may lead to minor competition with low-stature vegetation, but it is not known to form dense, ecologically damaging infestations in Hawaiʻi. Continued monitoring is recommended, and as with any naturalized non-native species, choosing native or low-risk alternatives is encouraged in sensitive restoration or conservation areas.
High Risk Traits:
- Has weedy races (e.g., shattercane) causing major crop losses
- Naturalized outside native range
- Broad climate suitability (tropical to temperate)
- Self-compatible, produces viable seed annually
- Hybridizes naturally with weedy relatives (S. halepense)
- Seeds dispersed intentionally by people and survive animal gut passage
- Tolerates grazing/mowing
- Host for numerous pests and pathogens
- Toxic to animals
Low Risk Traits:
- No spines, thorns, burrs, or allelopathic properties
- Not shade-tolerant (requires full sun)
- No vegetative reproduction; no long-term seed bank (>1 year)
- Well controlled by herbicides (glyphosate, glufosinate)
