Yellow Flag Iris Seeds iris pseudaconus -is a wetland plant that only grows in very wet soils at the margins of ponds, lakes, water meadows and damp ditches where it attracts a variety of insects including bees, dragonflies and ladybirds. In gardens it can easily be included at the edge of a pond or bog garden and will always grow best where there is some sunlight. Yellow Flag Iris has long pointed leaves that resemble swords, and spectacular yellow flowers from May to July. These are followed by unusual seed heads and seeds that provide autumn interest. Yellow Flag Iris looks best growing with other wetland plants such as Cuckooflower, and Ragged Robin. Alternative names for Yellow Flag Iris include Jacob’s sword, Wild Iris, Yellow iris, Segg and Yellow Flags