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 Japan.
The bluish purple color of the flowers of the Japanese garden iris is an example of the copigmentation phenomenon.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, Hanashōbu The 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.) 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.
Kakitsubata The grows in the semi-wet land and is less popular, but is also cultivated extensively.
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"):
Original text Pronunciation Meaningから衣
きつゝなれにし
つましあれば
はるばるきぬる
たびをしぞ思Karakoromo
Kitsutsu narenishi
Tsuma shi areba,
Harubaru kinuru
Tabi o shizo omouI have come so far away on this trip this time and think of my wife that I left in Kyoto
Kakitsubata at Ōta Shrine, Kyoto, is a National Natural Treasure. It was already recorded in a tanka by Fujiwara Toshinari also in the Heian period:
Original text Pronunciation Meaning神山や大田の沢のかきつばた
ふかきたのみは色に見ゆらむKamiyama ya ōta no sawa no kakitsubata
Fukaki tanomi wa iro ni miyu ramuLike the kakitsubata at Ōta Wetland, a God-sent heaven, my trust in you can be seen in the color of their flowers.
Ayame The is the iris typically growing wild on the dry land in Japan.
Characteristics Classification Color of flower Leaf Feature of flower Location Flowering timeHanashōbu Red purple, purple, etc. Distinct artery Shows no net Wet land Early June - late JuneKakitsubata Blue, purple, white, etc. Small artery Shows no net In water or wet land mid-May - late MayAyame Purple, rarely white Main artery not clear Shows net Dry land Early May - Mid-June
Note: Sweet flag, called shōbu () in Japanese, is a plant belonging to the family Acoraceae, genus Acorus, known for its fragrant roots, rather than its flowers.
See also Iris (plant)
References
External links Japanese Iris/Hanashobu Wall Paper Files (in Japanese) Japanese Iris/Hanashobu Photo Album 1 (in Japanese) Japanese Iris/Hanashobu Photo Album 2 (in Japanese)