Japanese Iris Roots

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Irises, the Rainbow Flower [a Rainbow], Flower-de-Luce

Phillip Miller

Gardener's Dictionary, 1732

Around the world, approximately 270 iris species are known plus hundreds of subspecies, collected forms, and natural hybrids. All come from the Northern Hemisphere and can be found growing as far north as Scandinavia and as far south as Florida, from Europe to Japan, as well as in many parts of North America. Their habitats range from mountainsides to deserts, open grasslands, dense woodland, and sandy coastal areas. Irises grow from 5 to 200 cm (2 in. to 6 ft.) tall and bloom from late winter to late summer. With just a small selection, a garden can have irises in bloom from the dark days of winter until summer turns to autumn.

Iris flowers come in a breathtaking array of colours ranging from white, yellow, and orange through every tone of blue, purple, pink, and brown to black. There are even green and red tones. All have six petals; the three upper petals are known as the standards, and the three lower ones as the falls. The base of the fall, the part of the petal that is narrower and constricted, is known as the haft or shoulder. The flowers bring into the garden not only colour but also scent. This fragrance can be fruity, musky, and spicy, like honey, and occasionally unpleasant.

Irises also produce very handsome linear foliage that contrasts perfectly against plants with differently shaped foliage, such as lungworts (Pulmonaria spp.), elephant's ears (Bergenia spp.), dead nettles (Laminum spp.), and hardy geraniums (Geranium spp.).

Irises are easy to grow, tolerating a wide range of conditions from very cold climates, where winter freezes the ground hard, right through to subtropical climates. Some irises like bright sunny borders with well-drained soil, others grow in dappled shade, and a handful thrive in full shade. Although some irises like acid soil, most grow in soil that is slightly acid to alkaline. Some like poor dry, stony soils, others grow in damp soil. Perhaps the best-known irises are those that grow in water.

The Plant and Flowers

Irises have been used symbolically for centuries in Europe and Asia. In Greek mythology Iris was the name of the rainbow goddess who passed messages between the heavens and earth. In doing so, she let her scarf scatter the fields below with the colours of the rainbow.

In another version of the myth, Iris was the messenger to Zeus born on the Greek island of Crete where the earliest known depiction ofirises exists. About 2100 B.C. a fresco was painted on the walls of the Minoan palace of Knossos in Crete, depicting a young man holding an iris. Some think it could be a Xiphium iris, but it could easily be a Juno iris. After all, Juno, the Roman goddess of the moon, was married to Zeus's Roman equivalent, Jupiter.

Irises have also been used in heraldry, an art form that developed to aid medieval knights in recognizing each other during battle. Accounts vary on how the

Differently shaped foliage

name 'Fleur-de-lis' came about. According to one legend the name dates back to the end of the fifth century, during a time when Clovis, the king of the Franks, a people who lived along the lower part of the Rhine, was at battle with the Goths. Being hemmed in, Clovis was shown where to safely cross the Rhine by the presence of the yellow flag iris, Iris pseudacorus. Afterwards he took it as a mascot. Later, during the twelfth century, the iris was incorporated by the French king Louis VII into the royal coat of arms and renamed the 'Fleur-de-Louis'. Then, during the fourteenth century the English king Edward III added the iris to his royal coat of arms during the battles to gain the throne from the French king Phillip VI. The iris remained in the British coat of arms until 1801.


In their abstract form irises can be found in ancient Persian embroidery and on tiles and pottery. In Japan irises have been used for centuries during festivals, and they have frequently been incorporated into embroideries and paintings, as well as being carved into crystal and jade.

Irises have often been portrayed in religious paintings, particularly those of the Virgin Mary and the birth of Christ. These include works by the most famous of painters, Leonardo da Vinci, Albrecht Durer, and Hugo van der Goes. Irises can be seen in vases, strewn across tables, and in a bunch of flowers together with lilies and columbines. In a painting of Queen Elizabeth I, which celebrates England's victory over Spain by the Armada, the virgin queen of England wears a dress embroidered with irises.

The iris is a flower of great beauty. The petals are translucent enough to allow light to shine through, brilliantly coloured, and three-dimensional in form. For these reasons irises have been used not only in religious iconology but also as subjects for many of Europe's famous painters. Dutch artists of the seventeenth century often combined bulbous irises with other cut flowers in their famous flower paintings, which nurserymen reportedly used as an early catalogue. In the nineteenth century, irises were featured in paintings by Auguste Renoir, Paul Cézanne, Vincent van Gogh, Odilon Redon, Paul Gauguin, and Claude Monet, whose garden at

Giverny in France still attracts many visitors during the iris flowering season. Elizabeth Blackadder, a well-known modern Scottish painter, has produced many beautiful watercolours with irises and cats.

Irises are also mentioned inliterature. William Shakespeare's play Anthony and Cleopatra refers to the iris as the 'vagabond flag', which indeed it is. Lord Byron, the nineteenth-century Englishpoet, also mentioned iris in his poem, 'Childe Harold's Pilgrimage':

Heaven is free

From clouds, but of all colours seems to be

Melted to one vast Iris of the West,

Where the day joins the past eternity


For centuries irises have been used in Europe and North America for medicine. Iris versicolor and I. pseudacorus produce iridin, or irisin, an odourless, bitter-tasting compound. In the United States, I. versicolor is known medicinally as blue flag. At one time it was used in a cure for syphilis, infections of the skin, and dropsy (edema). Today it is still an official drug used to purge the liver.

The roots of Iris 'Florentina', which is the white form of I. pallida, and I. germanica are known as orris root. In medieval times orris root was generally mixed with other herbs, such as hyssop, and honey, and used to treat stomach problems and skin disorders such as scrofula, which causes boils on the neck. In the mid-seventeenth century Nicolas Culpeper and John Gerard, writers of famous herbal books, documented the different ways in which orris root was used. It could be made into a potion to clear the body of phlegm, cramps, convulsions, and dropsy, and to cure choler (a liver dysfunction) and snakebites. To make the potion more palatable, it could be weakened with ale or wine. A poultice of orris root mixed with verdigris (a green substance that forms on copper), honey, and the root of the wild centaury was made to extract splinters from wounds.

During the nineteenth century orris root was cut into beads and bandaged on wounds that needed to be kept open. It was also used to alleviate bad breath. Servants who needed to disguise the smell of tobacco would chew chips of orris root, while wealthy gentlemen could suck lozenges. Chopped into thin sticks, the root was given to babies to chew during teething. Today it is still grown commercially in southern Europe and Morocco and used in toothpaste, tooth powder, and teething rings, but its most common use is in cosmetics and perfumes.


When freshly cut, iris roots have an earthy smell, but orris root contains irone, which, when dried over a long period, produces an ephemeral fragrance that is similar to violets. Pliny the Elder, a Roman scholar, mentioned that Iris pallida was used as an ingredient in perfume for wealthy people. It is still used today by the perfume industry as an essential oil and a fixative for other scents. It can be included in potpourri and scented sachets.

Author Gwendolyn Anley (1946) described a method for drying orris root so that it could be used in sachets to freshen linens and clothes in storage. She recommended lifting the rhizomes of Iris 'Florentina' or I. pallida in late July, washing them, and trimming the ends. Once cleaned up the roots should be peeled and then sliced into chips the width of a coin. The slices should then be laid on a wire rack to dry in a sunny spot that will not get rain, such as a greenhouse or cold frame. The chips must be turned occasionally until they are dry, then stored in an airtight bottle until required. The fragrance in dried orris root will last up to two years.


The flowers of irises have been used as a yellow dye and, when mixed with iron sulphate, the roots produce a black dye that is black enough to be used as a printing ink.

Irises have also been used as flavouring. Chianti, a local wine of Florence, was once flavoured with orris root. A piece of the root was placed into the vats to flavour the wine as it aged. The root has been used to flavour vermouth, gin, and some aromatic brandies. As a cooking ingredient, the leaves make a good sauce for fish, and the seeds, if peeled and roasted, can be used as a substitute for coffee.


As both a housekeeper and a gardener, I love flowers in the house. Many types of irises make good cut flowers. All the bearded irises, including the aptly named Table (Miniature Tall Bearded) irises, can be used. Although each flower lasts only a day or two, there are many more flowers to follow.

Irises should be cut before the bud unfurls. This is particularly important with bearded irises as they have delicate petals which tear easily. Place cut stems immediately into a bucket of water. Once indoors in a vase, keep the stems tidy by daily removing old flowers.

The Xiphium irises, which include Dutch irises, have been bred for the cut flower market and bloom during June. Spuria irises, which bear a resemblance to Dutch irises, bloom later in July and are also good for cutting, as are Japanese, Siberian, Sino-Siberian, Pacific Coast, and Louisiana irises. Indeed, in Japan, irises have been used for centuries for indoor decoration.

Indoor Flower Aril
Reblooming irises cut for autumn decoration: Iris 'Medway Valley', I. 'Pink Reprise', and I. 'Cordoba'

Botany and Classification

To better understand how irises differ from each other and from other groups of flowers, it is important to have a basic understanding of plant structure and plant relationships.


Irises grow from two types of roots, bulbous and rhi-zomatous. By far the largest number of species produce rhizomes, or underground stems, that create a storage system to enable the plants to survive in extreme conditions. The rhizomes can be large, as in the case of bearded irises, or small, as in the case of Siberian irises.

In some kinds of irises it is hard to see the rhizome, particularly when it comes to the water-loving types. All rhi-zomous irises produce fibrous roots, which die back each year so that new roots can be produced.

Bulbous irises also produce slender roots, but these emerge from the bottom of bulbs. Sometimes they are covered with a papery or netted overcoat. In the case of Juno irises, the roots are thick and fleshy.


Irises produce handsome leaves which can form broad clumps, upright tufts, or even creep along the ground. Bearded irises produce long, flat, sword-like leaves that are generally soft blue-green and create a fan. Others,

Water Iris Roots

Roots of Iris pseudacorus

Bearded iris roots

Siberian iris roots

Roots of Iris pseudacorus

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Bearded iris roots

Siberian iris roots

Bulbs of a Reticulata iris

Iris Dardanus

Roots of Iris 'Dardanus', an aril iris

Bulbs of a Reticulata iris

Roots of Iris 'Dardanus', an aril iris such as the Japonica irises, produce long dark green evergreen leaves. Siberian irises have slender, grassy leaves, while bulbous irises possess long, channelled leaves. Some irises have leaves that are tinted with purple at the base.


All iris flowers have at least six petals, although some Japanese irises produce more. The petals vary in size and shape from thin and strap-like to broad and rounded. Some flowers have beards sitting at the back

Evergreen Japanese Iris
Roots of Irisgraeberiana, a Juno iris Leaves of Dutch irises in early spring
Iris Roots

of the falls. Others, such as some aril irises, have beards on both the falls and the standards. All these plants are referred to as bearded irises, while those without beards are logically called beardless irises. Instead of beards they have colourful signals, raised ridges or crests. The style arms can also add a further dimension to the beauty of the iris flower. Most iris blooms are borne on tall, upright, branched stems; however, some of the smallest types are stemless.

The range of flower colours in irises is simply amazing—from white, yellow, orange, pink, and lilac to purple, blue, brown, and black with many tones and combinations of colour in between. No iris flower is truly red, although the Louisianas have orange-red tones.

In addition, the falls can be one colour, the standards another. The colours can be speckled, dotted, lined, and washed or layered over the petals. Among bearded or pogon irises the many different colour patterns have been given individual names, some of which are listed here. Occasionally these names are used to describe beardless and bulbous irises as well.

Amoena: White standards and coloured falls. Examples: Iris 'Crimson Snow', I. 'Seakist'. Bicolour: Standards one colour, falls another. Examples: Iris 'Edith Wolford', I. 'Instant Hit'. Luminata: Flower with an area of clear colour, which could be white, yellow, pink, or orange, and which surrounds the beard and shows as pale veining on darker falls. These flowers usually have petals with pale edges and style arms that are unmarked. Examples: Iris 'Fancy Dress', I. 'New Leaf'. Plicata: Light-coloured flower with darker-coloured stipples and lines around the edge of the petals. Examples: Iris 'Going My Way', I. 'Queen In Calico'. Self: Whole flower the same colour. Examples: Iris

'Mesmerizer', I. 'War Chief'. Variegata: Yellow standards and red falls. Examples: Iris 'Bengal Tiger', I. 'Blatant'.

When it comes to the shape of the petal, iris flowers range from flat, where all the petals are horizontal to the flower stems, to very upright. The petals can also be ruffled, some more extravagantly than others. The Tall Bearded iris 'Rare Treat' has ruffled petals, while the petals of Japanese irises 'Electric Rays' and 'Kaleido-show' are large and spreading, and those of Siberian irises 'Caezar' and 'Nora Distin' are both upright (standards) and drooping (falls).

Finally, iris flowers can be extremely fragrant. Despite what some authorities say, most Tall Bearded irises possess some kind of scent. Often it is thick and sweet, like honey, but it can be flowery, spicy, or as sharp as citrus fruit. Sometimes it is unpleasant and smells

Iris Mesmerizer

Iris 'Mesmerizer', a self

Iris 'Seakist', an amoena

Iris 'Instant Hit', a bicolour

Iris 'Mesmerizer', a self

Iris 'Seakist', an amoena

Iris 'Instant Hit', a bicolour

Peaches And Cream Siberian Iris
Iris 'Kaleidoshow', a Japanese iris with Iris 'Nora Distin', a typical Siberian iris Iris 'Rare Treat', a Tall Bearded iris with large, spreading petals with uprightstandards and droopingfalls ruffled petals

like cats. On a warm day a field ofbearded irises can be quite overpowering. Reticulata irises are said to have a violet scent. Iris graminea, a dwarf Spuria, is commonly known as the plum tart iris because of its fragrance. Some Juno irises smell like peaches, at least to me. It must be remembered, however, that scent is very personal and, like colour, everyone interprets these things differently.


Occasionally chromosomes are mentioned in the plant descriptions. For those, like myself, who are not botan-ically minded, chromosomes are the little rod-shaped bodies in the nucleus of a cell that carry the genes. Chromosomes come in sets referred to in this book as 'diploid' and 'tetraploid'. Diploid plants have two sets of chromosomes, while tetraploids have four sets. Hybridizers find it useful to know the chromosome count of the plants they are working with as plants with differing chromosome counts are difficult to cross-pollinate. Otherwise chromosomes help the gardener recognize certain types of plants. Diploid plants tend to be more delicate with smaller flowers and flower stems. Tetra-ploid plants often have bigger flowers with petals of greater substance, thicker stems, and a wider range of colours.


Many people think of plants simply as being there: growing every day, needing to be planted, watered, picked, eaten, or weeded out. To the botanist, plants present many fascinating questions, such as how do they relate to each other and, if plants look similar to one another, do they belong to the same family. To help answer these questions botanists devise family trees, but because plants cannot tell us their history in the same way humans can pass on their history from one generation to the next, these family trees are continually reassessed when new plants are discovered or new ways of looking at plants are developed. This system, known as classification, can also help the gardener. Classification tells us not only where a plant comes from but also where it can be grown and with which plants it will cross-pollinate to produce new hybrids.

Irises are members of the family Iridaceae, which includes, among others, crocuses, crocosmias, moraeas, and sisyrinchiums. Although the irises in this book originate from the Northern Hemisphere, other family members come from the Southern Hemisphere. Botanists divide the genus Iris into six subgenera. Plants are assigned to a subgenus based on their root system, form of the flower, seeds, seed pods, and distribution in nature. The first subgenus is once again called Iris and includes the bearded irises, sometimes called pogon irises, pogon being Greek for 'beard'. Next is subgenus Limniris, which includes the beardless irises, also called apogon irises, followed by four smaller subgenera: Nepalenis (not included in this book) and three bulbous subgenera, Xiphium, Scorpiris (Juno irises), and Her-modatyloides (Reticulata irises). Each subgenus may be divided into sections, which in turn are divided into species. Still smaller units of classification may be used. These categories are listed and defined here.

Genus: a group of closely related species Subgenus: a division of the genus Section: a division of the subgenus Species: the wild forms of a genus Subspecies: a form of a species

Variety: a selected or man-made plant grown in cultivation

Cultivar: a cultivated variety

Throughout the text I have usually used the word variety in its non-technical sense to mean cultivar as it is the more commonly used term.

Swedish botanist Carl Linnaeus first devised the botanical system in current use. He listed no more than 13 of the Iris species we know today. Over the years many new species have been described and included in the classification. Some were discovered to be hybrids of species and have since been removed. Further confusion can be created when botanists draw up alternative classifications.

The basic classification of genus Iris used today is based on work done by English botanist William Rickat-son Dykes, who published The Genus Iris in 1912. Other eminent iris authorities have since modified the classification. The subsequent work of George H. M. Lawrence (1953) and Georgi I. Rodionenko (1961) resulted in a reshuffling of Dykes's classification. Lawrence shifted the bearded irises into one section, including the aril irises with the pogon irises. A few years later

Rodionenko, a Russian botanist of great note, split the irises further, placing the bulbous species of section Xiphium (commonly known as Dutch and English irises) and the Juno irises into separate genera.

The story, however, does not stop there. In The Iris (1981), Brian Mathew drew up a further classification based largely on Dykes's work, but incorporating some alterations made by Lawrence and Rodionenko. An authority on irises, Mathew moved the Juno and Xiphium irises back into the genus Iris. In the present volume, I have followed Mathew's classification:

Subgenus Iris

Section Iris (bearded irises or pogons)

Section Psammiris

Section Oncocyclus

Section Regelia

Section Hexapogon

Section Pseudoregelia

Subgenus Limniris (beardless irises, or apogons) Section Lophiris (Evansia irises) Section Limniris Series Chinenses Series Vernae Series Ruthenicae Series Tripetalae Series Sibiricae (Siberica irises) Series Californicae (Pacific Coast irises) Series Longipetalae Series Laevigatae (Laevigata irises) Series Hexagonae (Louisiana irises) Series Prismaticae Series Spuriae (Spuria irises) Series Foetidissimae (Iris foetidissima) Series Tenuifoliae Series Ensatae Series Syriacae

Series Unguiculares (Iris unguicularis) Subgenus Nepalensis

Subgenus Xiphium (Dutch, Spanish, and English irises) Subgenus Scorpiris (Juno irises) Subgenus Hermodactyloides (Reticulata iris)

About This Book

This book arranges iris descriptions in three separate groups: bearded irises, beardless irises, and bulbous irises. These groups are subdivided into still smaller groups following the botanical classification of the genus.

In each chapter, the first plants to be described are the wild forms or species of the group, listed in alphabetical order by scientific name. The name of a species is always written in italics, as are the names of subspecies (subsp.), varieties (var.), and formas (f.).

Following the plant name is the name of the person who first discovered it and the year in which the plant name was published. In some cases in the past, the plant may have been known by another name, referred to as a synonym. The name in the text, however, is the current botanically correct name.

After the collector's name comes the country or countries in which the plant grows in the wild. The plant description follows.

All species can vary greatly, particularly if plants are distributed across a wide region. Colours, height, petal shape, and flower stems can be markedly different; however, the plants within a group of irises will have something in common, usually the shape of the seed. Therefore the flower description is as broad as possible.

Each species plant description concludes with the plant's height and flowering time in the wild. My main reference for this data was A Guide to Species Irises (1997), published by the Species Group of the British Iris Society. I have tried to be as general as possible when giving flowering times. This is because even here in Britain the blooming period of say, Tall Bearded irises, can vary by two to four weeks depending on where you live in the country. Britain being an island has a warm, wet oceanic climate and can have irises in bloom from midwinter to midautumn, which is generally from January to October. The bulbous Reticulata irises start the season and the reblooming, or remon-tanting, Tall Bearded irises end it. Most irises bloom from late spring to high summer, which is from May to mid-July in Britain. For those who garden in continental climates, where the winters come earlier and last longer, the flowering period may be more concentrated.

The second part of each chapter presents descriptions of the hybrids of the group, again in alphabetical order by scientific name. Hybrid names appear in regular font (not italics) and are enclosed by single quotation marks. The name of the hybridizer and the year the plant was registered follow the plant name and are enclosed in parenthesis. I have chosen to mention the year of registration rather than introduction as this information is more readily available, particularly for older cultivars. In most cases this information comes from documents filed at the time the iris was registered. Most of these details are logged with the American Iris Society and supplied by the hybridizer. They can be found in the American Iris Society registration Web site.

Following the description of the flower are the plant's height and flowering time. These data are very general as plants can vary when grown in different parts of the world. The flowering season is noted as early, mid, or late season. Early season hybrids open first; midseason hybrids, which tend to be in the majority, produce flowers in the middle part of a flowering period; and late season hybrids open towards the end of the main flowering period.

Hybrid plant descriptions end with the plant's parentage. The presence of a number of parenthesis indicates that some of the parents have not been introduced. The term 'sibling' is also used for irises that have not been registered but are related to plants from the same cross that have been introduced; the name of the known cross precedes the word 'sibling'. The parentage is given, not only as a general guide for those wishing to make their own crosses, but as a part of a hybrid's history. For those interested enough, the book contains varieties with parents that have also been described. By looking at these, it is possible to see where a plant gets its characteristics.

Iris Societies and Awards

Iris societies exist worldwide and are full of enthusiastic plant lovers. The British Iris Society, founded in 1922, and the American Iris Society, established in 1927, were among the earliest. Since then many more soci eties have been created. Some of these are very specialized, aimed only at a specific type of iris, while others are more general and often include all types of irises. Such groups are a wonderful way of meeting like-minded people and include individuals who breed and grow irises commercially. These societies usually produce informative bulletins, hold shows throughout the flowering season, and organize symposiums annually to enable iris lovers to exchange and gain information.

Iris societies also hand out awards to recognize members who are involved in the society and the best new plants. Although medals are awarded to all types of irises, the most important is the Dykes Medal. Irises to be judged are grown in trial grounds for several years and awarded points for their flowers and performance during the growing season. Awards are then given to the plants with the greatest number of points.

Yellow Siberian Apogon Iris
Showing irises at a local British Iris Society show
Paintings Irises

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  • Keke
    What type of iris has orange roots when young?
    7 years ago

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