This species is Quarantined: Class B Noxious Weed

This is considered a watch list species

Origin

Native to Europe

Habitat

Floodplain Forest, Lake or Pond, River or Stream, Yard or Garden. Iris pseudacorus can be found along the edges of lakes, ponds, rivers and streams and immersed in water up to 10 in. deep. It grows well in freshwater wetlands and can tolerate high acidity. In its native habitat, Iris pseudacorus can tolerate living in the upper zones of salt marshes, where it may be surrounded by saline water. The plant also tends not to favor calcareous substrates, though there are exceptions to this, such as along the Housatonic River of Connecticut.

Life cycle

The showy flowers of Iris pseudacorus bloom from April to June. The fruits are 1.6-2.7 in. long capsules. These capsules are 6-angled and cylindric-prismatic to ellipsoid in shape. The average capsule contains around 120 seeds that start out white, then harden and turn brown as the season goes on.

Ecological Threat

Iris pseudacorus forms large clonal populations that displace native species. The rhizomes of this plant are able to survive rather heavy droughts. Both the rhizomes and seeds of this plant can be transported downstream, allowing for further spread of the plant. The seeds of Iris pseudacorus can germinate even after a wetland area burns. In its native habitat, this plant is not widely grazed because of the glycosides it contains, making it poisonous to grazing animals. No birds are known to disperse the seeds of this plant. Iris pseudacorus is still sold and used for water gardens. Caution should be used when hand-pulling this plant, as it can cause skin irritation.