Appearance: Perennial aquatic herbaceous plant, grows 2 - 3' tall along shores in shallow water.
Leaves: Broad, flat, sword-shaped, stalkless, leaves embracing flower stalk.
Flowers: Deep yellow, 2 or 3 on one stalk, flower stalk round, shorter than outer leaves, three outer drooping sepals, with brownish mottled markings, surrounding the true flower; blooms May through July.
Seeds: Capsule containing numerous smooth, flattened seeds.
Roots: Reproduces vegetatively through horizontal stems growing below the soil surface, called rhizomes, forming roots and producing new plants.
- US Forest Service Fact Sheet
- To distinguish yellow iris (yellow flag) from native iris (northern blue flag): Mistaken Identity - Invasive Plants and their Native Look-Alikes