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Iris virginica (Virginia iris)
Smith, R.W.

Iris virginica

Iris virginica L.

Virginia Iris, Great Blue Flag, Southern Blue Flag

Iridaceae (Iris Family)



USDA Native Status: L48 (N), CAN (N)

A southern wetland species occurring from Virginia to Florida and Texas, Iris virginica is 3 feet tall with bright green leaves that often lie on the ground or water.

Southern Blue Flag is a member of the iris family (family Iridaceae) which consists of herbs growing from rhizomes, bulbs, or corms, with narrow basal leaves and showy clusters at the tips of long stalks. Flowers: usually radially symmetrical; calyx has 3 petal-like sepals; corolla has 3 petals; stamens 3. All these parts are attached at top of ovary. Leaves: simple, alternate, folded and overlapping one another at the base and aligned in two rows. There are about 60 genera and 1,500 species, distributed in temperate and tropical regions. Among them, Iris, Freesia, Gladiolus, Bugle Lily, and Montbretia are popular ornamentals. Saffron dye is obtained from Crocus, and "essence of violets," used in perfumes, is extracted from the rhizomes of Iris.


From the Image Gallery

9 photo(s) available in the Image Gallery

Plant Characteristics

Duration: Perennial
Habit: Herb
Fruit Type: Capsule
Size Notes: Up to about 3 feet tall.
Leaf: Green
Fruit: Green, Brown

Bloom Information

Bloom Color: White , Yellow , Blue , Purple , Violet
Bloom Time: May , Jun , Jul


USA: AL , AR , DC , FL , GA , IA , IL , IN , KS , KY , LA , MD , MI , MN , MO , MS , NC , NE , NJ , NY , OH , OK , PA , SC , TN , TX , VA , WI , WV
Canada: ON
Native Distribution: Coastal Plain from s.e. VA to TX
Native Habitat: Marshes; wet pinelands; swamps; wet meadows

Growing Conditions

Water Use: High
Light Requirement: Sun
Soil Moisture: Wet
CaCO3 Tolerance: Low
Soil Description: Moist, rich soils.
Conditions Comments: Southern blue flag is an ideal plant for edges of ponds, lily pools or drainage ditches. I. shrevei is the northern variety of this species.


Conspicuous Flowers: yes
Attracts: Birds
Deer Resistant: High


Description: Clump division is the usual method of increase. Divide in early fall when the leaves begin to turn yellow. Keep stringy roots attached to the stubby rhizome sections. If propagation is to made by seed, sow immediately in an outdoor seed bed. Seedlings
Seed Collection: Storage of iris seed greatly reduces viability.
Commercially Avail: yes

Find Seed or Plants

View propagation protocol from Native Plants Network.

National Wetland Indicator Status

This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1 (Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here for map of regions.

From the National Organizations Directory

According to the species list provided by Affiliate Organizations, this plant is on display at the following locations:

Lady Bird Johnson Wildflower Center - Austin, TX
Crosby Arboretum - Picayune, MS

Web Reference

Webref 38 - Flora of North America (2019) Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
Webref 23 - Southwest Environmental Information Network (2009) SEINet - Arizona Chapter

Research Literature

Reslit 834 - Parental origin and genome evolution in the allopolyploid Iris versicolor (2007) K. Y. Lim, R. Matyasek, A. Kovarik and A. Leitch
Reslit 965 - Seed germination characteristics of Iris virginica (1990) M. D. Morgan

This information was provided by the Florida WIldflower Foundation.
Search More Titles in Research Literature

Additional resources

USDA: Find Iris virginica in USDA Plants
FNA: Find Iris virginica in the Flora of North America (if available)
Google: Search Google for Iris virginica


Record Modified: 2023-02-14
Research By: NPC

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