1. Family: Iridaceae Juss.
    1. Genus: Iris Tourn. ex L.
      1. Iris japonica Thunb.

        Iris japonica is common in many parts of China and Japan and was introduced to Europe in 1792 from China by Thomas Evans of the East India Company. It was named in 1794 by Carl Peter Thunberg (1743-1828), a Swedish physician and botanist, who was a protégé of Linnaeus. Thunberg was employed by the Dutch East India Company and visited Japan from 1775-1778 (at a time when Japan was closed to most Europeans) and collected an impressive array of plants.

    [KSP]

    Kew Species Profiles

    General Description

    Iris japonica is common in many parts of China and Japan and was introduced to Europe in 1792 from China by Thomas Evans of the East India Company. It was named in 1794 by Carl Peter Thunberg (1743-1828), a Swedish physician and botanist, who was a protégé of Linnaeus. Thunberg was employed by the Dutch East India Company and visited Japan from 1775-1778 (at a time when Japan was closed to most Europeans) and collected an impressive array of plants.

    The great botanical artist Pierre-Joseph Redouté included a painting of this iris (known at that time as Iris fimbriata) in his Choix des plus belles Fleurs (1827-1833) (translation: 'Selection of the most beautiful flowers'), a fitting tribute to such a beautiful plant.

    Species Profile
    Geography and distribution

    A native of Japan (except Hokkaido), where it is common in wooded hills, and westwards to Burma and Sichuan in China, it occurs from 500-800 m (2,400-3,400 m in southwestern China). It is widely cultivated, and it is possible that the high-elevation plants from southwestern China are naturalised rather than native.

    Description

    Iris japonica is a perennial that spreads by creeping, above-ground rhizomes that root at intervals. The leaves are sword-shaped, evergreen and shiny green on one side but duller on the other. They are arranged in a broad fan and measure 30-80 cm long and 2.5-5.0 cm wide.

    The flowering stems are erect, branched, 30-80 cm long with white, pale blue or purple flowers measuring 5 cm in diameter. The falls (three of the six perianth segments in Iris ) have fringed margins and a yellow-orange crest. The flowers open in succession from March to May. The fruit is a capsule appearing from May-June.

    Two popular cultivars include Iris japonica 'Ledger' that has white flowers with purple markings and an orange crest, and I. japonica 'Variegata' with creamy-white striped leaves.

    Uses

    Iris japonica is widely cultivated as an ornamental, either as an outdoor plant (in sheltered areas) or in a cool greenhouse. It has received an Award of Garden Merit from the Royal Horticultural Society.

    In Chinese herbal medicine, the rhizome is used to treat injuries, and a decoction of the plant is used against bronchitis, rheumatism and internal injuries.

    Cultivation

    Iris japonica is easy to grow in warm temperate gardens or a cool greenhouse. Flowers can be susceptible to late spring frosts and will fail to flower after exceptionally cold winter weather.

    This species at Kew

    Iris japonica can be seen growing in the Duke's Garden.

    Kew's Economic Botany Collection contains samples of rhizomes of Iris japonica .

    Distribution
    Japan
    Ecology
    Grassy and rocky slopes, open forest margins in hills and among rocks by streams.
    Conservation
    Not evaluated according to IUCN Red List criteria.
    Hazards

    All parts of both wild and cultivated Iris are poisonous, especially the rhizomes (swollen stems).

    [KSP]
    Use
    Ornamental, medicinal.

    Images

    Distribution

    Native to:

    China North-Central, China South-Central, China Southeast, China Southeast, Hainan, Japan, Myanmar, Qinghai, Tibet

    Introduced into:

    Assam, East Himalaya, Italy, Réunion, Vietnam, West Himalaya

    Common Names

    English
    Fringed iris

    Iris japonica Thunb. appears in other Kew resources:

    First published in Trans. Linn. Soc. London 2: 327 (1794)

    Accepted by

    • Iwatsuki, K., Boufford, D.E. & Ohba, H. (2016). Flora of Japan IVb: 1-335. Kodansha Ltd., Tokyo.
    • Colasante, M.A. (2014). Iridaceae presenti in Italia: 1-415. Sapienza, Università Editrice, Roma.
    • Akhter, C. & al. (2013). A taxonomic appraisal of genus Iris L. (Iridaceae) in Kashmir himalaya, India Iranian Journal of Botany 19: 119-126.
    • Kress, W.J. et al. (2003). Checklist of the Trees, Shrubs, Herbs, and Climbers of Myanmar: 1-590. National Museum of Natural History, Washington, D.C.
    • Yutang, Z., Noltie, H.J. & Mathew, B. (2000). Flora of China 24: 297-313. Missouri Botanical Garden Press, St. Louis.
    • H?, P.-H. (1993). Câyc? Vi?tnam. An Illustrated flora of Vietnam 3: 603-1176. Pham-hoang Ho, Montréal.
    • Marais, W. (1978). Flore des Mascareignes 177: 1-16. IRD Éditions, MSIRI, RBG-Kew, Paris.
    • Ohwi, J. (1965). Flora of Japan (in English): 315-316. Smithsonian Institution, Washington, D.C.
    • Maire, R. (1959 publ. 1960). Flore de l'Afrique du Nord 6: 1-397. Paul Lechevalier, Paris.

    Literature

    Kew Species Profiles
    • World Checklist of Selected Plant Families (2010). Iris japonica. The Board of Trustees of the Royal Botanic Gardens, Kew.
    • Flora of China. Iris japonica. 24: 307.
    • Phillips, R. & Rix, M. (1991). Perennials, Vol. 1. Pan Books, London.
    • Stearn, W. & Rix, M. (1987). Redouté’s Fairest Flowers. Herbert Press/The British Museum, London.
    • Duke, J.A. & Ayensu, E.S. (1985). Medicinal Plants of China. Vol. 2. Reference Publications, Algonac, Michigan.
    • Ohwi, J. (1965). Flora of Japan. Smithsonian Institution, Washington D.C.
    Kew Backbone Distributions
    • Colasante, M.A. (2014). Iridaceae presenti in Italia: 1-415. Sapienza, Università Editrice, Roma.
    • Akhter, C. & al. (2013). A taxonomic appraisal of genus Iris L. (Iridaceae) in Kashmir himalaya, India Iranian Journal of Botany 19: 119-126.
    • Bahali, D.D., Sanjappa, M. & Rath, S.P. (2004). Geographical distribution of Iridaceae in India Indian Journal of Forestry 27: 251-256.
    • Kress, W.J. et al. (2003). Checklist of the Trees, Shrubs, Herbs, and Climbers of Myanmar: 1-590. National Museum of Natural History, Washington, D.C.
    • Yutang, Z., Noltie, H.J. & Mathew, B. (2000). Flora of China 24: 297-313. Missouri Botanical Garden Press, St. Louis.
    • H?, P.-H. (1993). Câyc? Vi?tnam. An Illustrated flora of Vietnam 3: 603-1176. Pham-hoang Ho, Montréal.
    • Marais, W. (1978). Flore des Mascareignes 177: 1-16. IRD Éditions, MSIRI, RBG-Kew, Paris.
    • Maire, R. (1959 publ. 1960). Flore de l'Afrique du Nord 6: 1-397. Paul Lechevalier, Paris.

    Sources

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2018. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    [A] © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2018. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    [B] © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Species Profiles
    Kew Species Profiles
    [C]
    [D] http://creativecommons.org/licenses/by-nc-sa/3.0