Pale Yellow Iris

Common Name: Pale Yellow Iris Scientific Name: Iris pseudacorus Habitat: shorelines - in water and on land, ornamental beds Provincial Designation: Prohibited Noxious Prohibited Noxious weeds are plant species that are designated as "prohibited noxious" in the Alberta weed regulation. Prohibited noxious weeds must be destroyed, meaning all growing parts need to be killed or the plant's reproductive mechanisms need to be rendered non-viable.

Origin

Pale yellow iris is native to Africa, Asia, and Europe and was introduced to North America in the mid-1800s as an ornamental plant for water gardens. It has also been used for erosion control and for making dyes and fibre.

Legislated Because

Pale yellow iris can out-compete native aquatic species along shorelines, forming dense thickets like native cattails. Rhizomes of this species form mats that trap sediment. Accumulated sediment causes open water to silt up.

Description

A key characteristic of this plant is large yellow to white flowers that are 8-10 cm wide. Each plant can have 4-12 flowers. Flowers have three large yellow petals and three downward-spreading yellow sepals with brown to purple patterns.

The leaves are flattened with a raised midrib and are 50-100 cm long and 10-30 mm wide.

Learn more about this species:

SeeFact Sheets - Alberta Invasive Species Council