Some of the plants in Birds of America are no less difficult to identify than the birds. One such plant is Louisiana Flag. The plant that most today would refer to as Louisiana Flag is a purple iris called the Giant Blue iris (Iris giganticaerulea). Governor Buddy Roemer signed Senate Bill No. 16 on July 18, 1990, that named the Giant Blue iris as the official state wildflower for Louisiana. In the later octavo edition of Birds of America, the Louisiana Flag that Joseph Mason drew changes from orange-copper to more of a purple color. Yet, Audubon labelled the plant in the octavo edition a “Coppery Iris, or Louisiana flag (Iris Cuprea).” Iris Cuprea has since been re-identified as Iris fulva.
However the Louisiana Flag plays out on the ground, it will be much farther up in the tops of Live oaks, Swamp tupelos, and other tall deciduous trees during the spring and summer months that the Blue Yellow-backed warbler will be practically impossible to see “gleaning amongst the leaves and branches.” The Blue Yellow-backed warbler is commonly known today as the Northern parula.