Background and aims

: The introduction of alien plant species for ornamental use represents a risk of invasion for ecosystems. Cenchrus advena, C. longisetus and C. setaceus are grass species introduced as ornamentals and highly cultivated in north- central Argentina, although their status in the invasion process is unknown. In this study, the presence of these three species is recorded, and their taxonomy, nomenclature and morphology are updated. In addition, presence maps and a key to differentiate them from congeners, both native and alien, are presented. The status of the invasion is analyzed and management recommendations are discussed.

M&M

: Herbarium specimens and new wild and cultivated plants were studied, and open access online database information were compiled.

Results

: We found 158 records of the three species distributed in 11 Argentine provinces, which allowed us to cite C. setaceus for the first time for the Argentine flora. A high proportion of naturalized records of C. setaceus and C. longisetus were found. Both species presented individuals established in disturbed natural environments of Córdoba province, initiating their state of propagation as invasives. Cenchrus advena was only found under cultivation.

Conclusions

: The invasive behavior of the grasses C. longisetus and C. setaceus found in Córdoba could be replicating in other provinces due to the high level of cultivation and propagule pressure. Therefore, it is urgent to stop their cultivation, monitor naturalized and invasive populations and replace their use with native species within the framework of sustainable development goals and current regulations.