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Summary
Duration	Perennial
Growth Habit	Forb/herb
U.S. Nativity	Native to U.S.
Federal T/E Status
National Wetland Indicator	OBL
Morphology/Physiology
Active Growth Period	Spring
After Harvest Regrowth Rate	None
Bloat	None
C:N Ratio
Coppice Potential	No
Fall Conspicuous	No
Fire Resistant	No
Flower Color	Blue
Flower Conspicuous	Yes
Foliage Color	Green
Foliage Porosity Summer	Porous
Foliage Porosity Winter	Porous
Foliage Texture	Coarse
Fruit/Seed Color	Black
Fruit/Seed Conspicuous	No
Growth Form	Rhizomatous
Growth Rate	Moderate
Height at 20 Years, Maximum (feet)
Height, Mature (feet)	3.3
Known Allelopath	No
Leaf Retention	No
Lifespan	Moderate
Low Growing Grass	No
Nitrogen Fixation
Resprout Ability	No
Shape and Orientation	Erect
Toxicity	None
Growth Requirements
Adapted to Coarse Textured Soils	No
Adapted to Fine Textured Soils	Yes
Adapted to Medium Textured Soils	Yes
Anaerobic Tolerance	High
CaCO3 Tolerance	Low
Cold Stratification Required	No
Drought Tolerance	None
Fertility Requirement	Medium
Fire Tolerance	None
Frost Free Days, Minimum	200
Hedge Tolerance	None
Moisture Use	High
pH, Minimum	4.8
pH, Maximum	7.3
Planting Density per Acre, Minimum	2728
Planting Density per Acre, Maximum	10912
Precipitation, Minimum	45
Precipitation, Maximum	65
Root Depth, Minimum (inches)	6
Salinity Tolerance	None
Shade Tolerance	Tolerant
Temperature, Minimum (°F)	12
Reproduction
Bloom Period	Spring
Commercial Availability	Routinely Available
Fruit/Seed Abundance	Low
Fruit/Seed Period Begin	Summer
Fruit/Seed Period End	Fall
Fruit/Seed Persistence	No
Propagated by Bare Root	No
Propagated by Bulb	Yes
Propagated by Container	No
Propagated by Corm	No
Propagated by Cuttings	No
Propagated by Seed	Yes
Propagated by Sod	No
Propagated by Sprigs	No
Propagated by Tubers	No
Seed per Pound
Seed Spread Rate	Slow
Seedling Vigor	Medium
Small Grain	No
Vegetative Spread Rate	Moderate
Suitability/Use
Berry/Nut/Seed Product	No
Christmas Tree Product	No
Fodder Product	No
Fuelwood Product	None
Lumber Product	No
Naval Store Product	No
Nursery Stock Product	Yes
Palatable Browse Animal	Low
Palatable Graze Animal	Low
Palatable Human	No
Post Product	No
Protein Potential
Pulpwood Product	No
Veneer Product	No

 

Kingdom  Plantae -- Plants

Subkingdom  Tracheobionta -- Vascular plants

Superdivision  Spermatophyta -- Seed plants

Division  Magnoliophyta -- Flowering plants

Class  Liliopsida -- Monocotyledons

Subclass  Liliidae

Order  Liliales

Family  Iridaceae -- Iris family

Genus  Iris L. -- iris P

Species  Iris virginica L. -- Virginia iris P

 

Alternate Names

Blue flag, southern blue flag, blue iris

 

Warning:  The roots of Virginia iris are toxic when taken internally, without sufficient preparation. 

 

Uses

Ethnobotanic: The Cherokee and other tribes in the southeastern United States are known to have used Virginia iris for its medicinal properties.  The root was pounded into a paste that was used as a salve for skin. An infusion made from the root was used to treat ailments of the liver, and a decoction of root was used to treat “yellowish urine.”  Virginia iris may have been one of the iris species used by the Seminole to treat “shock following alligator-bite.”

 

Status

Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values).

 

Description

General: Iris Family (Iridaceae).  Virginia iris is a perennial plant.  The slightly fragrant flowers (4 cm long, 7 cm across) consist of 3 horizontal sepals, or “falls,” and 3 erect petals.  The petals and sepals can vary in color from dark-violet to pinkish-white.  The sepals have a splash of yellow to yellow-orange at the crest.  Each plant has 2 to 6 flowers that bloom from April to May upon a single, erect, 3-9 dm tall stalk.  The stalk is sometimes branched and has a slight zigzag appearance.  The plant has 2 to 4 erect or arching, bright green, lance-shaped leaves that are flattened into one plane at the base.  Leaves are 1 – 3 cm wide and are sometimes longer than the flower stalk.  The fleshy roots (1-2 cm in diameter) are rhizomes that spread underground.  Pale brown, variably shaped seeds are born in three-part fruit capsules (3-6 cm long, 1-2 cm wide). 

 

Distribution: Virginia iris is common along the coastal plain from Florida to Georgia.  For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.

 

Adaptation

This plant grows in wet areas and sometimes in shallow water in both fresh and brackish tidal marshes.  It can be found in low savannas, thin woods and open meadows as well as along the edges of swamps, rivers, and ditches. 

 

Establishment

Virginia iris is a sturdy plant that is easy to grow and, once established, needs very little care.  They make lovely additions to the garden and are ideal for the borders of a garden pond.  This is because the plants prefer moist to wet soils that are high in organic matter.  The plants will grow best in mild climates where they can be grown in partial shade to full sun.  The plants can be grown from seed, but are easiest to propagate through division.  Seeds may be planted in the autumn, without pretreatment.  To propagate by division, divide the plants either after flowering or when the new leaves just begin to appear in the spring.  Cut the roots so that each piece contains a portion the feeding roots, the rhizome, and a leaf fan.  Place the rhizomes very near to the surface of the soil when planting.  Allow 45 to 60 cm between plants.  The plants grow best if divided every three to five years to thin out the colonies that form. 

 

Pests and Potential Problems

Snails are known to eat the leaves. 

 

Cultivars, Improved, and Selected Materials (and area of origin)  

These plant materials are readily available from commercial sources.  Contact your local Natural Resources Conservation Service (formerly Soil Conservation Service) office for more information.  Look in the phone book under ”United States Government.”  The Natural Resources Conservation Service will be listed under the subheading “Department of Agriculture.”

 

References

Bailey, L.H. & E.Z. Bailey 1976.  Hortus Third: A concise dictionary of plants cultivated in the United States and Canada. Simon and Schuster Macmillan Co., New York, New York.  1290 pp.

 

Chapman, A.W. 1883.  Flora of the southern United States: Flowering plants and ferns. Second Edition. J. Wilson and Son, Cambridge, Massachusetts.  698 pp.

 

Clinton, J. 2001.  Easy living native perennial wildflowers.  https://www.easywildflowers.com/quality/iri.virgi.htm

(12 June 2001). 

 

Cullina, W. 2000.  The New England Wild Flower Society guide to growing and propagating wildflowers in the United States and Canada.  Houghton Mifflin Company, New York, New York.  322 pp.

 

Duncan, W. H. & L.E. Foote 1975.  Wildflowers of the southeastern United States. University of Georgia Press, Athens, Georgia.  296 pp.

 

Godfrey, R.K. &  J.W. Wooten 1979.  Aquatic and wetland plants of southeastern United States.  Vol 1.  University of Georgia Press, Athens, Georgia.  712 pp.

 

Greene, W.F. & H.L. Blomquist 1953.  Flowers of the south: native and exotic.  University of North Carolina Press. Chapel Hill, North Carolina.  208 pp.

 

Moerman, D.E. 1998  Native American ethnobotany. Timber Press, Portland, Oregon.  927 pp.

 

Ottensen, C. 1995.  The native plant primer.  Harmony Books, New York, New York.  354 pp.

 

Small, J.K. 1933.  Manual of southeastern flora. University of North Carolina Press, Chapel Hill, North Carolina.  1554 pp.

 

Smith, A.I. 1979.  A guide to wildflowers of the Mid-south.  Memphis State University Press, Memphis, Tennessee.  281 pp

 

Steffek, E.F. 1983.  The new wild flowers and how to grow them.  Timber Press, Portland, Oregon.  186 pp.

 

Sturtevant, W.C. 1954.  The Mikasuki Seminole: medical beliefs and practices.  Doctoral Dissertation, Yale University.  538 pp.

 

Tiner, R.W. 1993.  Field guide to coastal wetland plants of the Southeastern United States. University of Massachusetts Press, Amherst, Massachusetts.  328 pp.

 

Prepared By:

Diana L. Immel

USDA, NRCS, National Plant Data Center, c/o

Environmental Horticulture Department, University of California, Davis, California

 

Species Coordinator:

M. Kat Anderson

USDA, NRCS, National Plant Data Center, c/o Environmental Horticulture Department, University of California, Davis, California

 

Edited: 21June2001 jsp; 20may03 ahv

 

For more information about this and other plants, please contact your local NRCS field office or Conservation District, and visit the PLANTS Web site<https://plants.usda.gov> or the Plant Materials Program Web site <https://Plant-Materials.nrcs.usda.gov>

 

 

 

Attribution:  U.S. Department of Agriculture