Iris virginica is a perennial plant. The plant has 2 to 4 erect or arching, bright green, lance-shaped leaves that are flattened into one plane at the base. Leaves are 1–3 cm (1⁄2–1+1⁄4 in) wide and are sometimes longer than the flower stalk. The fleshy roots (1–2 cm or 1⁄2–3⁄4 in in diameter) are rhizomes that spread underground. Pale brown, variably shaped seeds are born in three-part fruit capsules (3–6 cm or 1+1⁄4–2+1⁄4 in long, 1–2 cm or 1⁄2–3⁄4 in wide).