This plant is a hybrid of two native American irises, meaning it is a cross between two distinct species of native iris plants. The name iris is after the Greek goddess of the rainbow, because irises come in many colors.

Iris x robusta 'Gerald Darby' has blue- violet flowers with yellow signals on stems 2 to 3 feet tall in late spring, and typically there are 2 to 3 blooms per stalk. The leaves have shades of purple in the spring that fade by summer, making this a very attractive spring plant. It is a hybrid of two native American irises, I. versicolor and I. virginica. It does well in moist to wet soils on the edges of a pond or stream. It forms clumps which can be divided in late spring.

The classic Fleur de Lys, which has been a symbol of royalty throughout history, is an adaptation of the iris flower.