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Yellow Flag Iris

Photo by Ray Curran

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Common Name: Yellow flag iris
Scientific Name: Iris pseudacorus
Origin: Europe, Asia and Africa


Yellow iris is an herbaceous perennial that can grow between 3-4 ft. The broad, lance-shaped leaves are stiff and erect. The yellow, showy flowers bloom from April to June.


Yellow iris is found along the edges of lakes, ponds, rivers and streams. It grows well in freshwater wetlands and can tolerate high acidity.


This plant forms large, clonal populations that displace native species and offer nutrient-poor forage for wildlife.


Caution should be used when hand-pulling this plant, as it can cause skin irritation. Digging up the root ball of individual plants can be effective. Native blue flag iris is a good landscaping alternative to this ornamental, wetland invader.

Regional Distribution


WNY PRISM Priority

Tier 4 – Local Control

Invasive Species Priorities – Tier Chart


Yellow flag iris was introduced to the U.S. as an ornamental plant and has been planted for erosion control. Yellow flag spreads through seeds and rhizome growth.

Yellow flag iris is a prohibited species in New York State – for more information on Prohibited and Regulated Species, visit

Native Alternatives 

Blue flag iris (Iris versicolor)

Cardinal flower (Lobelia cardinalis)

Canada lily (Lilium canadense)

Stiff goldenrod (Solidago rigida)


This map shows confirmed observations (green points) submitted to the NYS Invasive Species Database. Absence of data does not necessarily mean absence of the species at that site, but that it has not been reported there. For more information, please visit iMapInvasives.