WSU Clark County Extension
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Yellow Flag Iris

Scientific name: Iris pseudacorus
Taxonomy
Family:Iridaceae
Type:Invasive plants
Native:NO
Plant Requirements
Zone:4 to 9
Moisture:Wet
Plant Characteristics
Height:6 ft
Width:6 ft
Bloom:Summer flowers
Bloom Time:May to June
Bloom Color:Yellow
Additional Characteristics
Trees


Fruit

Leaves


Bark
Wildlife value

Poisonous
Description Iris pseudacorusis is a wetland plant that is especially showy during its short blooming period. This good-looking plant has been transplanted into well-watered gardens all over the world and has widely escaped; it is also used in sewage treatment, and is known to be able to remove metals from wastewaters.

  Morphology:
This weed is classified as an herbaceous perennial which spreads by underground rhizomes and seeds. During the summer it produces very showy, yellow iris flowers borne on long, dark green, flattened, sword-like leaves.

  Adaptation:
Iris pseudacorus was brought into the United Sates in the early 1900’s and sold as an ornamental plant. It soon escaped and quickly took up residence all across the continent in marshes, and rivers. Iris pseudacorus, a fast-growing and fast-spreading invasive plant, can out-compete other wetland plants, forming almost impenetrable thickets, in much the same way as cat-tails will.

  Pests:
None.
For assistance, contact Dr. Charles Brun (brunc@wsu.edu), (360) 397-6060 5701
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