The beginning of May is the time for many purple-flowered plants to bloom, including lilac, allium, spiderwort and, especially, iris. There are more than two hundred different species of iris and, while the most common color of an iris flower is, indeed, some shade of purple, iris flowers can actually be a number of colors, including purple, lavender, white, yellow, orange, pink, blue and brown. I even have grown one that was basically black!

Irises blooming in my garden in Monmouth, Illinois, 2021

Irises are native to southern Europe and the Mediterranean and were introduced to Egypt from Syria by Thutmose III, sixth Pharaoh of the Egyptian Eighteenth Dynasty in 1469 B.C. Irises are now grown widely, especially in the northern hemisphere. The rhizomes of the Dalmatian or sweet iris (iris Pallida) and of the bearded iris (iris germanica), known in English as orris root (iris arida in Latin; ἴρεως ῥίζα in Greek), have been used for perfume and for medicinal purposes, especially in antiquity. Today the plant is occasionally used in aromatherapy. Orris, by the way, is an unexplained corruption of iris which has been used to refer to the root or its powder since the 16th century. It is also known to herbalists as Queen Elizabeth root.

The iris is the state flower of Tennessee, the February birth flower and the 25th wedding anniversary flower. The flower has been depicted in architecture, coats of arms, coins and shields for centuries. The most well-known artistic representation of the flower today is probably van Gogh’s Irises (1889), now in the J. Paul Getty Museum.

The flower gets its name from the Greek ἶρις (“iris”), which can refer either to the rainbow or to Ἶρις (“Iris”), the goddess of the rainbow.

Probably the earliest reference in Greek to ἶρις (“iris”) as the rainbow, occurs at Iliad 17.547–552 where Zeus extends a “dark-shimmering rainbow (πορφυρέην ἶριν) out of heaven to be a sign for mortals of either war or a chilling storm. This passage suggests the link between the goddess Ἶρις (“Iris”) and the rainbow ἶρις (“iris”): both are messengers. Iris is the messenger of Zeus and the rainbow can serve as a celestial sign to mortals. The rainbow has a similar function in the story of Noah and the flood in the book of Genesis, where the rainbow is a sign of a covenant between God and humans:

12 And God said, “This is the sign of the covenant I am making between me and you and every living creature with you, a covenant for all generations to come: 13 I have set my rainbow in the clouds, and it will be the sign of the covenant between me and the earth. 14 Whenever I bring clouds over the earth and the rainbow appears in the clouds, 15 I will remember my covenant between me and you and all living creatures of every kind. Never again will the waters become a flood to destroy all life. 16 Whenever the rainbow appears in the clouds, I will see it and remember the everlasting covenant between God and all living creatures of every kind on the earth.” (New International Version).

The Greek word πορφυρέην (porphyreen), used to describe the rainbow at Iliad 17.547, is usually translated as some form of “dark” in order to emphasize the approaching storm, but the word is more generally associated with the color purple. The English word “porphyry,” derived from πορφυρέη (porphyree), refers to the color purple and, in particular, to a deep purple igneous rock prized by the ancients for its decorative quality. Especially associated with royalty, the rock was known as “imperial” porphyry and was often used in sculptural depictions of Roman emperors and for their sarcophagi, such as the sculpture of the Tetrarchs, sacked from the Byzantine Philadelphion palace in 1204, and now at the Treasury of St. Marks, Venice and the sarcophagus of Helena, the mother of the emperor Constantine, now in the Vatican Museum.

While Iliad 17.547–552 is the only place in Homer that the word ἶρις (iris) refers specifically to the rainbow, the goddess herself appears several times as messenger in the Iliad (but never in the Odyssey). Like many of the Greek deities she is anthropomorphic and is described by a number of epithets which refer to her feet in her role as messenger, including ποδήνεμος (“wind-footed” 5.353); ἀελλόπος (“storm-footed,” 24.77); and πόδας ὠκέα (“swift-footed,” 3.129, an epithet which she shares with Achilles, the hero of the Iliad. One epithet, χρυσόπτερον (“golden winged,” 11.185), stands out for its association of the goddess with a color, but nowhere in the Iliad is the goddess Iris described as multi-colored like the rainbow. Nevertheless, the Greek use of the same word to refer to both goddess and rainbow makes the two synonymous. Linguistically, at least, Iris is the rainbow and the rainbow is Iris. Like other Greek deities, then, Iris is a nature deity and is a personification of a natural phenomenon.

The link between the flower and the rainbow was implicitly made in a book About Colors, which survives in the corpus of Aristotle (but which may have been written by one of his students). In this book, the author describes variation of scents, juices and colors in different parts of plants and says that “So it happens that very different scents and juices are associated with both flower and fruit. This is still more obvious in the case of the flowers themselves, for, in the same petal, part may be black and part red and in some cases part may be white and part purplish (πορφυροειδές, porphyroeides). This is specially true of the iris; for this plant has many differences in colour during its ripening….” (De Coloribus 796b 19–29, translation by W.S. Hett in Aristotle. Minor Works: On Colours. On Things Heard. Physiognomics. On Plants. On Marvellous Things Heard. Mechanical Problems. On Indivisible Lines. The Situations and Names of Winds. On Melissus, Xenophanes, Gorgias. Loeb Classical Library 307. Cambridge, MA: Harvard University Press, 1936). Note the author’s reference to the many colors of the iris flower (like the rainbow), including the color purple (πορφυροειδές, porphyroeides).

In English the word “iris” first appears in 1490 in reference to the rainbow in Encydos a romance translated from the French by the British merchant William Caxton (c. 1422 — c. 1491). The iris flower is first mentioned in English in a 1562 Herbal by the English naturalist William Turner (1509/10–13 July 1568), who says that in English it is known as the “flour de lys” (i.e., the fleur de lys).

In 1592 William Shakespeare is the first English writer to mention the goddess Iris. In Henry VI III, ii. 407, Queen Margaret, sending the Duke of Suffolk off on a mission to France says

Let me hear from thee; 405
For wheresoe’er thou art in this world’s globe, 406
I’ll have an Iris that shall find thee out. 407

Greek and Roman authors also applied the word ἶρις (“iris”) to a variety of other objects. In his book on meterology, in which he devotes considerable attention to rainbows, Aristotle also uses ἶρις (“iris”) to refer to the ring or “halo” which forms around the moon. In his book on the house, Theophrastus describes how the tips of a peacock’s feathers are ringed with a rainbow. In 1826 the entomolgists Kirby and Spence used the word “iris” to describe the inner ring of an eye-like spot on an insect’s wing.

The Roman naturalist Pliny the Elder mentions a hexagonal prismatic rock crystal which he calls an iris. This rock, found on an island in the Red Sea, gets its name, according to Pliny, “in token of its appearance, for when it is struck by the sunlight in a room it casts the appearance and colours of a rainbow on the walls near by, continually altering its tints and ever causing more and more astonishment because of its extremely changeable effects. (ex argumento vocatur iris, nam sub tecto percussa sole species et colores arcus caelestis in proximos parietes eiaculatur, subinde mutans magnaque varietate admirationem sui, Natural History 37; 136–37; translated by D. E. Eichholz in Pliny, Natural History, Volume X: Books 36–37, Harvard University Press, 196s). So Pliny’s iris could be translated into English as “rainbow rock” or “Iris rock.” According to Bostock and Riley (in The Natural History. Pliny the Elder. John Bostock, M.D., F.R.S. H.T. Riley, Esq., B.A. London. Taylor and Francis, Red Lion Court, Fleet Street. 1855), this stone may be either “Hyalin quartz iridized internally, or prismatic crystals of Limpid quartz, which decompose the rays of the sun.” In the same passage, Pliny also mentions another stone, iritis, which is similar to the iris rock in every respect, but which is much harder. A reference to Pliny’s iris rock by the Cornish writer John Trevissa (fl. 1342–1402 A.D.) in his 1387 translation of the Latin chronicle entitled Polychronicon by Ranulf Higden is probably the earliest appearance in English of the word “iris”.

In his On the Usefulness of the Parts of the Body, the 2nd-century A.D. Greek physician Galen also used ἶρις (“iris”) to refer to the ring in the ciliary region of the eye, perhaps because it is darkly pigmented. In a 1525 medical tract, Jerome of Brunswick offered the earliest reference in English to the iris of the eye and explained that the iris is that which gives the eye color.

In his Inquiry into Plants (IX, ix, 2), Theophrastus, the 4th-century B.C. Greek Peripatetic, refers to ἴρινον μύρον (irinon), an isis-based perfume. In his Histories (XXX.26) Polybius mentions irinon as one of the perfumes used for anointing in the gymnasium following the games celebrated by Antiochus IV of Macedonia in 166 B.C. ­­­­­

Related to ἶρις (“iris”) is the Greek word ἰριώδης (iriodes), which can be translated “like a rainbow” and gives us the word “iridescent.” In his book on meterology, Aristotle used the Greek word to describe the multi-colored ring of light which sometimes forms around a candle. The earliest reference in English to the many-colored iris or rainbow appears in 1601 in William Shakespear’s All’s Well that Ends Well (I.iii.156–159), where the Countess asks Helena

What’s the matter,
That this distemper’d messenger of wet,
The many-colour’d Iris, rounds thine eye?
Why? that you are my daughter?

Like the dark rainbow Zeus sends mortals in the Iliad, the many-colored rainbow round Helena’s eyes is a sign of her tearful sorrow.

Ancient Greek and Roman physicians used iris root for various medicinal purposes. Especially in his book on the Method of Medicine Galen, for example, described how he used iris root in poultices, purgatives, and other medicines, especially for the treatment of inflammation in various organs. In his book De Medicina (On Medicine, 3.10) the 1st-century A.D. Roman encyclopoedist Celsus recommended iris root for headaches.

Herbalists today continue to recognize the purgative properties of orris root, which can be used as a diuretic, emetic or cathartic. In large doses, however, it can induce severe nausea, vomiting, purging and colic. In earlier times, orris root was used for a variety of medicinal purposes, including the treatment of bronchitis and chronic diarrhoea, and as a remedy in dropsy. The root was sometimes chewed as a remedy for bad breath.

The dried root is especially used as a perfume, especially in potpourris, in sachet powders and in dentifrices, toothpowders and cachous. According to A Modern Herbal, first published in 1931, by Mrs. M. Grieve, the dried powder of orris root can be used as a snuff to encourage sneezing to relieve cases of congested headache. It was sometimes also added into the rinse water in laundries in order to give a refreshing scent to the cloth. Mixed with anise, powdered orris root was employed as a perfume for linen in England as early as the late fifteenth century.

Oil of Orris, distilled from powdered orris root, has an intense violet scent and is very expensive. It is used commercially in creating the finest perfumes, often blended with other scents to strengthen and prolong their odor. It is also used in the production of some gins.

In 1803 the English chemist Smithson Tennant (30 November 1761–22 February 1815), one of the discoverers of a silvery-white platinum-type metal, named the element (77Ir) iridium after the Greek goddess Iris because of the striking and diverse colors of its salts.

A wide number of other English words are formed from “iris” with its various connotations. Referring to the rainbow or displaying the colors of the rainbow are: “iridal” and “iridian,” belonging to or pertaining to the rainbow; “iridical,” brilliant with rainbow colors; “iridine,” rainbow-like; “iirised,” having the colors of the rainbow. Formed from “iridescent,” displaying the colors of the rainbow are “iridescence;” “iridescency;” “irisation,” the process of making iridescent’ “iridize,” to make iridescent; and “iridization.“ Pertaining to the iris plant are: including: “iridaceous” or “irideous,” i.e., belonging to the genus Iris. Medical terms referring to the iris of the eye include: “iridian;” “iridomotor,” pertaining to the movement of the iris; “iridotomy,” a cutting of the iris; “iridectomy,” the cutting out of a potion the iris of the eye; “iridotome,” a knife for removing the iris; “irideremia,” congential absence of the iris; “iridochoroiditis,” inflammation of the iris and the choroid coat of the eye; “iridocyclitis,” inflammation of the iris and the ciliary body; “iridoscope,” instrument for examining the iris; and “iridodesis,” a surgical procedure to secure the iris. Referring to the element iridium are: “iridious,” containing iridium; and “iridiate,” a salt of iridic acid;

At various times and in various cultures, the iris flower has been considered to represent a number of symbols, including royalty, victory, power, wisdom, friendship, faith, hope, passion and purity. Perhaps the most important of these historically is royalty, especially because of the flowers association with the color purple, long a color of kings and of royalty. In particular, the iris as a power symbol is seen in the fleur de lys. While “Fleur de lys” (also “fleur de lis”) literally means “lily-flower” in French, the flower in question is actually more likely a representation of the iris known as the iris florentina (although there is some scholarly debate about this). The “fleur de lys” was used as the symbol of French and Spanish royalty and also appears on the national coat of arms of Albania and Bosnia-and- Herzegovina; of the province of Quebec, Canada; and of the municipalities of Florence and Parma in Italy and New Orleans, Louisiana. Some organizations, like the New Orleans Saints sports team, and Scouting, also include the fleur de lys in their logos. Stylized irises even appeared on the staffs of ancient Egyptian pharaohs and their wives.

The people of Florence, Italy, are especially proud of their association with the iris, which they call giaggiolo. The fleur de lys, which has appeared on the giglio (“lily”) on their historical civic banner since 1251, associates the city with its ancient Roman name of Florentia (City of Flowers). The purple giglio is also the logo of the Fiorentina football club.

Every year in May the city hosts a major iris breeders’ show and competition at the Giardino dell’Iris, a botanical garden near the Piazzale Michelangelo, where more than a thousand iris varieties are on display. My wife and I had the great pleasure of visiting the giardino in May, 2011 and can highly recommend the show. Here is a photo gallery of our visit to the giardino.

Irises at the Giardino dell’iris in Florence, Italy, May, 2011

So the next time you look at an iris flower, think of its many historical and cultural associations.

I taught Classics for 40+ years and am now Capron Professor Emeritus of Classics at Monmouth College in Illinois. Read more about me at

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