Gladdon iris, also known as Iris pseudacorus, is a perennial flowering plant that can grow up to four feet in height. This water-loving plant produces bright yellow flowers that bloom from May to July. Aside from its scientific name, Gladdon iris has several other synonyms. It is commonly referred to as yellow iris, flag iris, water flag, and dagger flower. These alternate names are based on the plant's physical appearance and preferred growing environment. Yellow iris is the most widely used synonym, and it accurately describes the plant's vivid yellow color. Overall, the Gladdon iris is a stunning plant with several common names that can be used interchangeably.