Cortaderia selloana | Pampas-grass
First reported in the wild
Invasive species - risk of Medium Impact
Introduction pathways - 1
Escape from Confinement
Introduction pathways subclass - 1
NAPRA Ireland risk assessed
Tussock forming plant (may be more than 1m across), with distinctive erect culms (stem, specifically of sedges and grasses) up to 3m high (Stace, 1997). Prominent feathery panicles (inflorescences or clusters of flowers) at fruiting, panicles generally silvery white (Stace, 1997).
In France the areas invaded by C. selloana had lower species richness and diversity, and less plant cover compared to uninvaded areas (Domènech et al., 2006). Invasion is heavily linked to anthropogenic (man made) disturbance, the presence of Cortaderia decreases with increasing distance from urban areas and land use changes being positively correlated with invasion (Domènech et al., 2006). Part of the success of Cortaderia may be due to its ability to respond better than native plants to low water availability (Vourlitis & Kroon, 2013), suggesting that invasion and associated impacts would be concentrated in the south east of the country.
Inland unvegetated or sparsely vegetated habitats
Gynodioecious (species are either hermaphrodites or female) with females producing ten times as much seed as hermaphrodite plants, with female plants producing 40,000 - 60,000 seeds on average, compared to 4000 - 6000 in hermaphrodite plants (Domènech, 2005). Seeds are wind dispersed and tend to germinate better on disturbed ground (Domènech & Vilà, 2006).
Pathway and vector description
Popular garden plant,planted in gardens and spreads into the wild from there. Sold under a variety of names and a range of cultivars with slight colour variations including Cortaderia 'Pink Feather', C. 'White Plume', C. 'Pumila', C. 'Splendid Star' and C. 'Blue Bayou'.
Mechanism of impact
Cortaderia selloana is a ruderal plant (a plant species that colonises bare ground) and is generally found on waste ground and Cortaderia recruitment appears to be linked to soil disturbance (Domènech & Vilà, 2006 ; Domènech & Vilà, 2007; Reynolds, 2002).
Occasional - Localised & Rare. Almost certainly under recorded as it is a popular garden plant. Bias in distribution towards the south east may be due a true distribution or an artefact of recording effort.
Native to Brazil, Uruguay, Argentina, Chile & Paraguay, it has been introduced into Australia, New Zealand, USA and parts of the Mediterranean regions in Europe, particularly France (GISD, 2005).
Date of first record category
Fifty year date category
Records submitted to Data Centre in 2023
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How can you help
Report any sightings to the National Biodiversity Data Centre.
Delivering Alien Invasive Species In Europe (DAISIE) project list this species as one of the 100 Worst Invaders in Europe.
Domenech, R., & Vila, M. (2007). Cortaderia selloana invasion across a Mediterranean coastal strip. Acta Oecologica, 32(3):255-261. Reynolds, S.C.P. (2002) A catalogue of alien plants in Ireland. National Botanic Gardens. Glasnevin, Dublin. Stace, C. (1997). New Flora of the British Isles 2nd Edition. Cambridge University Press, Cambridge. Domènech, R., & Vilà, M. (2006). The role of successional stage, vegetation type and soil disturbance in the invasion of the alien grass Cortaderia selloana. Journal of Vegetation Science, 17(5):591-598. Domènech R, 2005. Cortaderia selloana invasion in the Mediterranean region: invasiveness and ecosystem invasibility. PhD thesis. Bellaterra, Barcelona, Spain: Autonomous University of Barcelona. Global Invasive Species Database, 2005. Cortaderia selloana. [Online]. Domènech, R., Vilà, M., Gesti, J., & Serrasolses, I. (2006). Neighbourhood association of Cortaderia selloana invasion, soil properties and plant community structure in Mediterranean coastal grasslands. Acta Oecologica, 29(2), 171-177. Vourlitis, G. L., & Kroon, J. L. (2013). Growth and resource use of the invasive grass, pampasgrass (Cortaderia selloana), in response to nitrogen and water availability. Weed Science, 61(1), 117-125.
Global Invasive Species Database