Iris versicolor L. – Northern Blue Flag Iris

General: Perennial herb; stems 20─80 cm tall, in small colonies from thick rhizomes.


Leaves: Basal and alternate on stem, sword-shaped, usually extending as high as the flowers, sheathing the base and often purplish.


Flowers: Showy, 6–8 cm wide, blue-purple, with yellowish veins; flower parts in threes; large flower parts are sepals, the inner, smaller three are petals.


Fruits: Cylindrical capsules, 3–5 cm long, with flat seeds, stacked inside, turning dark brown in autumn (a useful identification feature after flowering).


Where found: Along shores and in marshes, swamps, wet meadows and occasionally fens; from Newfoundland to southern Manitoba, south to Minnesota and Virginia. Grow best in full sun but tolerate partial shade.


Notes: This species has been designated Quebec’s provincial flower.


Irises are eaten by the iris borer, a moth whose larvae live in the leaves eat their way to the rhizomes, killing the plant. Hollow rhizomes indicate that this parasite is present.



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