Family: Poaceae
“After a critical review of the collections at BISH, PTBG, US, and HAW, all specimens formerly identified as Schizachyrium condensatum from Hawaiʻi have been reidentified as S. microstachyum, based on a recent revision of the group showing that the name S. condensatum has been widely misapplied to a complex of closely related, but unique, species (Welker & Peichoto 2015). In Hawaiʻi, S. microstachyum is often and easily confused with Andropogon bicornis and A. tenuispatheus.” … “During roadside surveys on Maui, the first population of this grass was found on the island in the Haʻikū area, consisting of approximately 500 plants. Schizachyrium microstachyum is abundant on Hawaiʻi Island, with most of the population centered between Hilo and Kahuku, with very large stands of this grass occurring in the Volcano area; smaller populations are found on Kauaʻi, where this grass is widespread but relatively uncommon. Small populations also exist on Oʻahu and Maui.” (Faccenda 2024).
High Risk Traits:
- Forms dense, fire-prone stands that increase fire frequency and intensity
- Resprouts vigorously after fire
- Displaces native vegetation and prevents regeneration
- Tolerates wide elevation range (210–1,310 m), showing environmental versatility
- Facilitates invasion by more aggressive grasses (e.g., Melinis minutiflora)
- Seeds adapted for long-distance wind dispersal (fluffy plume, slow fall rate)
- Produces viable seed and can flower within first year
- Thrives in disturbed habitats (roadsides, open areas)
- Unpalatable to goats, reducing herbivory control
Low Risk Traits:
- No spines, thorns, or toxicity
- No vegetative reproduction (no rhizomes)
- Sensitive to glyphosate (herbicide-controllable)
- Shade-intolerant, limiting spread into intact forests
