The iris blossom is unique in its shape, revered as a symbol of royalty in France, the fleur-de-lis. Parts of the flower are always in multiples of three. In general, three upright petals are called the "standards" and the three horizontal or drooping petals are called the "falls". Slight variation occurs on this generality between beardless and crested irises.
The bearded iris flower is comprised of three ruffled and oval petals that are held upright in the center, called the "standards". Just outside the standards are three larger additional petals that usually droop or flex backwards called the "falls". Upon each fall petal is a yellowy cluster of male flower parts that shed pollen, called the "beard". In the central core of the flower, partially hidden by the standards is the female floral parts, the style arms, that are stiff and waxy, often fragrant. Within the style arms are the stigmas, where pollen is received and fertilizes the ovaries to later form seeds.
Bearded or German bearded irises, in all their classifications, display this flower type.
Beardless iris also has floral parts in multiples of three, the main difference when compared with bearded iris is the lack of the beards as well as smaller, more open petals.
Three spreading, tongue-like petals are the "standards". Just inside the standards are three small ruffled style arms that house the female floral parts. Below the style arms, and outside the standards are the three larger sized "falls", which have a wedge-like band of color called the "signal". In both the standard and fall petals, the lower part of the petals narrow into a shoulder-like area known as the "haft".
Examples of beardless types include Siberian and Louisiana irises.
Instead of a beard, crested irises have a crest or ridge on each of the falls.
In the core of the flower are three waxy style arms that often have jagged edges. Immediately under the style arms are the "standards". These three standards are usually uniform in color and texture and often have a toothed or lobed end. Finally, under the standard petals lay the slightly larger and more ornate "falls". The falls, also numbering three, have minutely jagged edges and in their center is crest or ridge of tissue where the "hafts", or narrowed neck of the fall, occurs.
Evansia iris is another name for a crested iris, and a common example is the dwarf crested iris, Iris cristata.