Microseason: Irises Flower

SUMMER

SUMMER SOLSTICE

IRISES FLOWER

26 - 30 June

Mid-summer in the Japanese archipelago means that irises begin to unfurl their distinctive blooms. Irises carry medicinal significance, as well as aesthetic. Though often grouped together under the term “iris,” in Japan we categorize irises into three types: shobu, ayamé, and kakitsubata. Each refers to a different species with unique habitats, forms, and cultural associations.

The plant most directly linked to ritual and medicinal use is shobu. It is not a true iris, but a member of the sweet flag family. Growing in wetlands and along rice paddies, shobu is valued for its sharp, herbal fragrance. On 5th May, fresh shobu leaves are placed in the bath to thwart misfortune and illness, and keep young children healthy for the year ahead. It’s a custom that dates back to the 800s. The leaves were believed to protect households, while the rhizome was used in remedies for digestive ailments and to stimulate circulation.

Ayamé, a true iris species, thrives in relatively dry soils such as grasslands and riverbanks. The flower features intricate markings at the base of each petal. These veins distinguish ayamé from other iris varieties and have made it a subject of seasonal verse for hundreds of years. Unlike shobu, which is valued for its medicinal properties, ayamé has been cherished primarily as a symbol of elegance and ephemeral beauty. It appears in poetry and court diaries.

The third type is kakitsubata. This plant prefers wet environments such as marshes and garden ponds. The flower has smooth petals with little to no veining, and its vivid purple or blue hues have made it a staple in Japanese gardens since at least the 1300s. In the rinsen-style gardens associated with Zen culture, kakitsubata is often planted around reflective water to emphasize seasonal transition. Kakitsubata also holds a special place in Japanese literary culture that then influenced painting, like Ogata Korin's well-respected six panel byobu screens made of sweeping brushwork of mineral pigments and gold leaf.

During the Edo period, the cultivation of irises became increasingly specialized. Garden manuals and illustrated horticultural guides documented the emergence of dozens of cultivated varieties. Hybrid irises, bred for unusual colors or petal shapes, were prized in samurai estates. This season is still reserved for viewing of these flowers in gardens and public parks.

Photo credit: Momoko Nakamura