The term "Japanese iris" encompasses three species of Irises cultivated in gardens or growing wild in Japan: hanashōbu (Iris ensata), kakitsubata (Iris laevigata) and ayame (Iris sanguinea). Of these three species, I. ensata is the one most commonly referred to as "Japanese iris" outside of Japan.
The Hanashōbu (ハナショウブ, 花菖蒲?, Iris ensata var. ensata, syn. I. ensata var. hortensis I. kaempferi) grows in the wet land and is the most extensively cultivated variety in Japanese gardens. According to the place where it was cultivated, it is classified into the Edo (Tokyo), Higo (Kumamoto Prefecture), Ise (Mie Prefecture), American (U.S.A.) and other series. It is extensively grown in gardens throughout the temperate zones. Several cultivars have been selected, of which 'Rose Queen' and 'Variegata' have gained the Royal Horticultural Society's Award of Garden Merit.
It is a prefectural flower of Aichi Prefecture due to the famous tanka poem which is said to have been written in this area during the Heian period, as it appears in The Tales of Ise by Ariwara no Narihira (note that the beginning syllables are "ka-ki-tsu-ha (ba)-ta"):
Tsuma shi areba,
Tabi o shizo omou
I have come so far away on this trip this time and think of my wife that I left in Kyoto
Kamiyama ya ōta no sawa no kakitsubata
Fukaki tanomi wa iro ni miyu ramu
Like the kakitsubata at Ōta Wetland, a God-sent heaven, my trust in you can be seen in the color of their flowers.
|Classification||Color of flower||Leaf||Feature of flower||Location||Flowering time|
|Hanashōbu||Red purple, purple, etc.||Distinct artery||Shows no net||Wet land||Early June - late June|
|Kakitsubata||Blue, purple, white, etc.||Small artery||Shows no net||In water or wet land||mid-May - late May|
|Ayame||Purple, rarely white||Main artery not clear||Shows net||Dry land||Early May - Mid-June|
- Anthocyanin-flavone copigmentation in bluish purple flowers of Japanese garden iris (Iris ensata Thunb.) T. Yabuya, M. Nakamura, T. Iwashina, M. Yamaguchi and T. Takehara, EUPHYTICA, Volume 98, Number 3, 163-167, doi:10.1023/A:1003152813333
- "RHS Plant Selector - Iris ensata 'Rose Queen'". Royal Horticultural Society. Retrieved 2013-05-20.
- "RHS Plant Selector - Iris ensata 'Variegata'". Royal Horticultural Society. Retrieved 2013-05-20.