Iris (noun).

1.plants with sword-shaped leaves and erect stalks bearing bright-colored flowers composed of three petals and three drooping sepals.
2.muscular diaphragm that controls the size of the pupil which in turn controls the amount of light that enters the eye; it forms the colored portion of the eye.
3.female name

The word comes from Greek mythology. Iris is the personification of the rainbow and messenger of the gods. As the sun unites Earth and heaven, Iris links the gods to humanity. …

In Japan iris always played a prominent role in cultural traditions. It’s one of the symbols of Japan, its 3 petals symbolize faith, valor and wisdom. There are many different kinds of iris flowers in Japan:
Ayame, taller hanashobu (about 300 varieties grown here)(it’s primarily this type of iris, introduced to the West in the mid-nineteenth century, that graces gardens in North America), kakitsubata (most celebrated in  Japanese poetry and art), and shobu(sometimes called “sweet flag”. This plant still continues to be used in Chinese and japanese herbal medicine. Leaves of iris are believed to be useful for growth of children. Parents in Japan put the leaves into bath water for their children.

Iris has been one of the most favorite flowers for Japanese people from the ancient times until today. The flower has inspired the people with passion of love and dignity. Already in the 10th century iris was praised as a symbol of love in the famous book of love romance, Ise Monogatari. In Tokugawa period, iris gardens were opened at many places around Edo (now Tokyo), especially in the east of Sumida river. Most of them gave way to urban development, but fortunately the oldest one remains today. Horikiri iris garden was opened at the beginning of the 19th century. About 200 species of irises are in full bloom each June.