鸢尾（学名：Iris tectorum），又名屋顶鸢尾（中国植物学杂志）、蓝蝴蝶（广州）、紫蝴蝶、扁竹花（陕西）、蛤蟆七（湖北），为鸢尾科鸢尾属的植物。

多年生草本，根茎匍匐多节，节间短，剑形叶交互排列成两行，花茎与叶同高，总状花序，春季开蝶形蓝紫色花，1-3朵，外列花被的中央面有一行鸡冠状白色带紫纹突起。花、根、叶有小毒。

Iris tectorum (also known as roof iris, Japanese roof iris and wall iris) is a species in the genus Iris, it is also in the subgenus of Limniris. It is a rhizomatous perennial. It is native of China, Korea and Burma, with lavender-blue, bluish-violet, purple-blue, blue-lilac or sky blue flowers. There is a white form as well. It is a compact plant and is cultivated as an ornamental plant in temperate regions.