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Facts About the Iris Flower

By Isabel Prontes ; Updated September 21, 2017

Iris is the name of a genus of about 260 different species. The genus is comprised of perennial flowering plants, all of which are notable for their attractive flowers. The name "iris" is derived from "rainbow" in the Greek language. It was called rainbow in Greek due to the many colorful varieties of irises in existence (however, they are most often purple). They are part of the Iridaceae family.


Irises appear all over the north temperate zone. They show up in diverse landscapes and climates all over Europe, the Middle East, North America, Asia and Africa. Irises exist in meadowlands, riverbanks and montane areas.


There are many different varieties of the iris flower in existence. Some well-known and popular examples include the bearded iris, sweet iris, white cemetery iris, dalmatian iris, crested iris, orjen iris and the English iris. The bearded iris is also known as Iris germanica and is a hardy perennial that is low maintenance. Sweet iris is notable for its bluish-violet flowers that have a pleasant fragrance. They are also known for their tri-colored foliage. The white cemetery iris (also known as Iris albicans) is a natural and sterile hybrid with greyish-green leaves that are broad and shaped like swords. The dalmation iris (Iris pallida) originated in the former Yugoslavia and has greenish-blue leaves with sword shapes. The crested iris (Iris cristata) features pale blue, violet and white flowers. Orjen iris (Iris orjenii) is a rare cultivar that has greenish-blue leaves and appears on grassy slopes. The English iris (Iris latifolia) is popular due to its attractive flowers and is found in northwestern Spain. The flowers are dark blue with yellow marks.


Irises are known for having showy appearances. Their stems are erect and long and can be branched, hollow, solid or flat. Rhizomatous varieties tend to have between three and 10 basal leaves, which are shaped similarly to swords (they appear in tight and dense clusters). Bulbous varieties, instead, have basal leaves that are cylindrical. The inflorescences of the iris flower are shaped like fans.


Iris flowers are commonly used as ornamental plants. They appear in botanical gardens and also residential gardens. This is due to their pleasant appearance and also because they are simple to propagate and cultivate. They thrive in most free, garden-quality soil types.


As with any plant, various diseases could cause damage to iris flowers. Some common diseases that affect these plants include blossom blight, bacterial leaf spot, bacterial soft rot, rhizome rot and crown rot. Some ways to handle and eliminate these diseases include practicing proper sanitation; elimination of old stems, leaves and plant debris during the autumn; use of beneficial nematodes; and use of chemical insecticides.


The iris is a hardy plant. It thrives in full sun but can generally manage partial shade. A minimum of six hours of daily sun is necessary. Well-drained soil is preferable when cultivating irises. The plants should not be planted too deep into the soil. Without adequate drainage, irises rapidly rot. Every three to four years, dividing of irises is necessary.