Yellow Flag Iris

May is Invasive Plant Species Month in British Columbia, making it the perfect time to share information on a commonly known plant in the park, Yellow Flag Iris. While this plant might be appealing to the eye, it can be harmful to native plants, and can be toxic to humans and animals.

Yellow Flag Iris is typically found in ditches, shallow ponds, marshes, and along still and slow-moving water courses. This perennial herb has flattened, sword-like leaves that support three yellow flowers. This plant was introduced from the Mediterranean region as an ornamental plant and reproduces by rhizomes and seeds.

These plants can create a thick mat underwater that connects several hundreds of plants, damaging wildlife habitat and native vegetation.

To learn more about Yellow Flag Iris and how you can take action, please visit

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