Iris japonica (fringed iris)
Fringed iris is common in many parts of China and Japan and appears to have been cultivated in Europe since 1792.
About this species
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) (“Selection of the most beautiful flowers”), a fitting tribute to such a beautiful plant.
Geography & 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.
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.
Illustration from Curtis's Botanical Magazine
Hand-coloured engraving of Iris japonica (as Iris chinensis) by an unknown artist in Curtis’s Botanical Magazine (1797).
Curtis’s Botanical Magazine (Editor: Martyn Rix) provides an international forum of particular interest to botanists and horticulturists, plant ecologists and those with a special interest in botanical illustration.
Now well over two hundred years old, the Magazine is the longest running botanical periodical featuring colour illustrations of plants. Each four-part volume contains 24 plant portraits reproduced from watercolour originals by leading international botanical artists. Detailed but accessible articles combine horticultural and botanical information, history, conservation and economic uses of the plants described.
Published for the Royal Botanic Gardens, Kew by Wiley-Blackwell Publishing.
See the Wiley-Blackwell Subscription Information page for rates (for both print and online).
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.
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
Kew’s Economic Botany Collection contains samples of rhizomes of Iris japonica.
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