Irises have been grown in gardens since time immemorial and the first document related to irises grown in gardens dates back to sometime around 1479 B.C., a little while after Egypt's King Thutmose III triumphed over Syria. It is said that King Thutmose III's staff included a plant specialist whose job was to discover new plants for his king.
In fact, King Thutmose III was himself an enthusiastic gardener and, according to available documents, he yearned for as well as prized plants in the same manner as some people long for gold. He was so fascinated by the flowers he came across in Syria, such as tulips, irises, roses, lilies and crocuses that he wanted to take them to his country and plant them in his personal garden. When the plants started producing flowers in Egypt, the king took a decision to memorialize his Syria conquest by including the blooms in the Temple of Amon he built at Karnak. The carvings of irises as well as the other flowers on the walls of the temples can be seen even till this day.
In the ancient times, people of the Indian as well as Egyptian cultures employed the rhizomes of iris for therapeutic purposes as well as to make perfumes. While the perfumes made from iris rhizomes were used to apply in the form of offerings to deities, the by-products of the plant such as the orris roots were tossed into fires to produce aromas that would please the gods. Several centuries after this, in the 19th century, the use of dehydrated iris rhizomes became a key industry in Florence in Italy. In fact, the iris was also made the insignia of Florence. On the other hand, people in Germany hung the orris roots in barrels containing beer with a view to keep the beverage fresh. People in France also used orris roots in their wine casks with the same purpose.
King Louis VII of France reached Egypt sometime during the Crusades in the 12th century and found irises growing in that country. He carried irises to France and espoused the flower as a mark of his conquest. In fact, he was the first to carve the fleur-de-lis on his coat of arms.
As early as the 500s, the Frankish ruler Clovis I also adopted the iris or fleur-de-lis as his insignia after he converted to Christianity. For several centuries, the practice of adopting the fleur-de-lis as a royal emblem continued in France. For instance, in 1376, French King Charles V carved as many as three fleurs-de-lis on his coat of arms. Gradually, the concept was adopted by people in other countries too. Today, the fleur-de-lis is the symbol of New Orleans in the United States, while the iris has been adopted at the official State Cultivated Flower in Tennessee.
As irises are indigenous to the Northern Hemisphere, these plants only attain their utmost perfection in places that come under the North Temperate Zone. Nevertheless, the flowers still grow in many places of the Southern Hemisphere. In their southern limit, irises are found growing on the coasts of North Africa, but not any further down south. It is believed that irises were pushed to this southern limit during any one of the various Ice Ages. On the other hand, Alaska, the Gaspe Peninsula and north-eastern regions of Asia form the northern limits for irises.
The ancient Roman kingdom was set up in the 6th century B.C. and it developed into a powerful empire to cover a vast region what is currently known as Europe, the nations on the eastern border of the Mediterranean Sea and North Africa over the next few centuries. At the close of the second century A.D., the Roman Emperors had not only triumphed over the lands in the region of the Mediterranean, but also encircled the sea, counting Syria and Egypt, which is home to several iris species. In due course, the ancient Romans set up trading routes all over the Mediterranean region. While they mainly traded in wheat and olive oil along with other commodities, the Roman ships also transported irises as well as other decorative plants. The roots of irises were transported all over the Roman Empire, counting the lands located in the north of the Mediterranean Sea. Soon, many Roman gardens across the empire, including those lying on the northern edge of the sea, started growing irises successfully.
A few centuries following the Roman Empire's decline and fall in the 4th and 5th centuries A.D., Islamic rulers invaded the entire region from North Africa as well as the Middle East throughout Europe up to the Iberian Peninsula. In Spanish history, these invasions are referred to as the Moorish conquests. Along with them, the Moors introduced a rich plant heritage, counting the cultivated plants, and the irises were very prominent among them. For several centuries, irises were successfully grown in walled gardens of the castles of the Moorish rulers. Among these, the most famous walled garden was located inside the Alhambra, an armed palace in Grenada in Spain.
With Columbus venturing out to discover new lands in 1492, it was the start of the age of exploration. During the same time, Isabella and Ferdinand, Columbus' sponsors, also hounded the Moors out of Spain. In addition to these two historical events, the resulting friendship among the neighbouring nations in the region, including Portugal, Spain as well as the Low Countries, which included Holland, resulted in extensive distribution of the garden plants that were brought in by the Moors. In fact, the endowed gardeners and plant growers of Holland are credited with developing several initial strains of the Spanish, English, German and Dutch irises, which are actually the forerunners of several iris varieties that adorn our gardens in contemporary times.
When the new settlers arrived in ships to the New World, they carried with them several ornamental plants, including several irises species. As early as in the 1600s, gardeners in Virginia had already included irises in their lists of preferred plants. Even in those days, irises formed the basis of home gardens as well as public gardens all over the newly-established colonies. For several years, the early settlers were familiar with only one native iris, which was known as the blue flag. They discovered several other native iris species much later. These native irises included the Appalachian Mountains iris, a dwarf variety, the Pacific Coast iris and the Louisiana iris.
An English physiologist named Sir Michael Foster (1836 - 1907) is credited with making several connections with plant collectors, missionaries as well as friends across the globe, thereby becoming the first individual to sincerely assemble, grow as well as breed several irises from the wild. In England, Sir Michael Foster was the first person to cultivate large irises he collected from Asia Minor. Obviously, these iris species were tetraploid irises which were later responsible for a number of major enhancements in the irises species that are grown in the gardens.
Sir Foster was serious regarding growing irises and, hence, maintained comprehensive records as well as drawings of the irises he cultivated. William Rickatson Dykes (1877 - 1925), was a friend of Sir Foster and encouraged by Sir Foster, he embarked on a task of studying the complete genus that includes irises. In fact, Dykes was very sincere about his role as a botanist. He was of the view that apart from studying all iris species in the herbaria of America and Europe, it was also his duty to thoroughly examine those that grew in the wild, prior to writing anything regarding them. He developed a garden of his own with donations received from Sir Foster which grew in size and popularity as he collected iris seeds as well as plants from different regions of the world.
In present times, the work done by Dykes is rather out-of-date, but we should not forget that he was the first person in the world to undertake a study of the irises and thereby provided the world with a solid knowledge base regarding these plants. In contemporary times, taxonomists are equipped with latest tools as well as enhanced knowledge, which help them in classifying the irises. However, during the period when Dykes worked, botanical cataloguing is mainly based on the visible features of the plants, for instance the shape of the seeds, variety of the seedpods and the arrangement of the tube-shaped perianth that is found between the flower and its ovary. In current times, botanists can also avail chromosomal information and, hence, are able to describe the relationships among various iris species better. Very often, botanists across the globe continue to discover new iris species, which leads to changes in the classification as well as the science related to the irises.