| Toxicity | Toxic. Livestock, dogs, cats and humans. |
| Control | Mechanical, cultural and herbicide. Contact your county weed district or local Applicator for more information. |
| Habitat | Along shorelines, ditches, stream banks, floodplains, forests, areas of shallow water, low-lying wetlands and fish ponds. |
| Root | Extensive root system. |
| Leaf Shape | Sword-like with smooth edges. |
| Lifespan | Perennial; two years or longer. |
| Priority 2A Weed | Common in isolated areas of Montana. |
| Similar Looking Plants | Cattails or Rocky Mountain iris when it is not flowering. |
| Important Information | This plant is currently sold as an ornamental. Each large seedpod can produce 120 seeds. Yellowflag is of two species of iris known to occur in Montana outside of horticultural plantings; the only yellow one. |
