Iris versicolor, also commonly known as the Harlequin Blueflag, Larger Blue Flag, Northern Blue Flag, and other variations of those names, is a species of Iris

Iris (plant)

Iris is a genus of 260-300species of flowering plants with showy flowers. It takes its name from the Greek word for a rainbow, referring to the wide variety of flower colors found among the many species...

native to North America where it is common in sedge meadows, marshes, and along streambanks and shores.

Growth

I. versicolor is a perennial herb, growing 10–80 centimetres high. This iris tends to form large clumps from thick, creeping rhizome

Rhizome

In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...

s. The unwinged, erect stem

Plant stem

A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...

s generally have basal leave

Leaf

A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

s that are more than 1 cm wide. Leaves are folded on the midribs so that they form an overlapping flat fan. The well developed blue flower has 6 petal

Petal

Petals are modified leaves that surround the reproductive parts of flowers. They often are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals lying...

s and sepal

Sepal

A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...

s spread out nearly flat and have two forms. The longer sepals are hairless and have a greenish-yellow blotch at their base. The inferior ovary is bluntly angled. Flowers are usually light to deep blue (purple and violet are not uncommon) and bloom during May to July. Fruit is a 3-celled, bluntly angled capsule. The large seeds can be observed floating in fall.

The blue flag is the provincial flower of Quebec

Quebec

Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....

, having replaced the Madonna lily

Madonna lily

Lilium candidum is a plant in the genus Lilium, one of the true lilies. It is native to the Balkans and West Asia. It forms bulbs at ground level, and unlike other lilies, has a basal rosette of leaves through the winter, which die back in summer...

 which is not native to the province.

Chemical constituents

The species has been implicated in several poisoning cases of humans and animals who consumed the rhizome

Rhizome

In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...

s, which have been found to contain a glycoside

Glycoside

In chemistry, a glycoside is a molecule in which a sugar is bound to a non-carbohydrate moiety, usually a small organic molecule. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. These can be activated by enzyme...

, iridin

Iridin

Iridin is an isoflavone, a type of flavonoid. It is the 7-glucoside of irigenin and can be isolated from several species of irises like orris root, Iris florentina or Iris versicolor, also commonly known as the larger blue flag....

. The sap can cause dermatitis

Dermatitis

-Etymology:Dermatitis derives from Greek derma "skin" + -itis "inflammation" and genetic disorder.-Terminology:There are several different types of dermatitis. The different kinds usually have in common an allergic reaction to specific allergens. The term may describe eczema, which is also called...

in susceptible individuals.