Cortadeira, also known as pampas grass, is present in at least 208 municipalities in mainland Portugal, according to a 2025 study that placed it among the ten invasive species with the widest distribution in the country. This plant, native to South America, is frequently found along roadsides, coastal areas, riverbanks, private gardens and public spaces.
Specialist Hélia Marchante, professor at the School of Agriculture of the Polytechnic University of Coimbra, warned that the invasion is already established and rapidly progressing, stating that each delay in intervention increases costs and makes controlling the species more difficult. The research advocates early action on new outbreaks, before the plant becomes dominant.
Cortadeira has been included in the National List of Invasive Species since 2019, with its possession, cultivation, trade, transport and ornamental use prohibited. However, Hélia Marchante noted that the national plan for Cortadeira, prepared by the Institute for Nature Conservation and Forests (ICNF), remains unpublished and unimplemented, although legislation provides for surveillance mechanisms and action plans.
In addition to environmental risks, the plant poses dangers to human health due to the allergenic nature of its pollen. Late flowering can prolong pollen exposure into Autumn, creating a second season of risk, particularly in Mediterranean regions. Researchers advocate coordinated action between central government, municipalities, protected area managers and citizens in identifying and eliminating the plant.
