Bloomipedia
Giant blue iris (Iris giganticaerulea)
Photo: Jody Shugart via iNaturalist · CC BY 4.0 · resized

Flower profile

Giant blue iris

Iris giganticaerulea

Giant blue iris (Iris giganticaerulea) is a flowering plant in the Iridaceae family, native in the lower 48 states, blooming mostly March–April across the U.S.

★ Official state wildflower of Louisiana (1990)Native to Louisiana

Giant blue iris is a wildflower that USDA PLANTS lists as native in the lower 48 states. In Louisiana it's most often seen in bloom in March–April.

1states where USDA records it
300LA sightings*
343U.S. sightings*

*iNaturalist research-grade observations, as of October 17, 2026.

On our lists for: Louisiana

🏅
Louisiana's official state wildflower since 1990. Visit the Louisiana page → La. R.S. 49:154.1

Quick look

Iris giganticaerulea, the giant blue iris, or Louisiana Iris, is a species of iris, in the subgenus Limniris, in the series Hexagonae. It is a rhizomatous perennial, from northern America. It has long bright green leaves, very tall stems and one or two musky fragrant flowers in a range of blue shades or rarely white.

  • It belongs to the Iridaceae family. iNaturalist
  • USDA PLANTS describes it as an herb (forb) with a perennial life cycle. USDA PLANTS
  • USDA PLANTS lists it as native in the lower 48 states and records it in 1 states. USDA PLANTS
  • NatureServe lists it as native to Louisiana. NatureServe
  • In Louisiana, most iNaturalist sightings of it in flower come in March–April. iNaturalist
  • iNaturalist has 300 research-grade sightings of it in Louisiana, ranking #107 among the 154 flowers on our Louisiana list. iNaturalist

When does it bloom?

In Louisiana, most flowering sightings come in March–April.

Flowering records by month in Louisiana (iNaturalist research-grade observations marked “Flowering”) (68 records)

Conservation status

Federal (U.S. ESA)
Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. USFWS ECOS
NatureServe global
GNR Not yet ranked worldwide. NatureServe
Louisiana
No list Louisiana has no state list of endangered or threatened plants separate from the federal list, so we show federal status and NatureServe's Louisiana ranks. NatureServe: S3, vulnerable in Louisiana.
Rare elsewhere
Other states where NatureServe ranks it rare or missing: FL (S2), MS (S1). (S1 critically imperiled, S2 imperiled, SH possibly extirpated, SX presumed extirpated.)

Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.

Please leave it where it grows

Please don't pick or dig this flower: NatureServe ranks it S3 in Louisiana. NatureServe

Can you eat it?

For peopleNot well documented

None of the sources we checked (NC State Extension (no page for this plant), USDA PLANTS) say whether it's edible or poisonous for people.

For petsToxic to dogs, cats and horses

ASPCA's entry “Flag” (Iris species), which covers the whole genus, lists it as toxic to dogs, cats and horses. Signs include: Salivation, vomiting, drooling,lethargy, diarrhea. Highest concentration in… ASPCA

🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.

Where does it grow?

USDA PLANTS records giant blue iris in 1 states.

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Louisiana.

Louisiana counties with USDA records: Assumption, Caddo, Caldwell, Cameron, East Baton Rouge, Jefferson, Natchitoches, Ouachita, Richland, St. Charles, St. Mary, Washington, West Feliciana.

Names, range and relatives

Other scientific names (synonyms in USDA PLANTS): Iris alticristata, Iris aurilinea, Iris citricristata, Iris elephantina, Iris fluviatilis, Iris miraculosa, Iris paludicola, Iris parvicaerulea, Iris rivularis, Iris venulosa, Iris wherryana.

County records: USDA PLANTS lists it in 13 counties across 1 states; the most are in Louisiana (13).

Other Iris on Bloomipedia (11): Irises, Yellow iris, Dwarf crested iris, Douglas iris, Western blue flag, Northern blue flag iris, Southern blue flag, Oregon iris, Dwarf iris, Beach-head iris.

More from the Iridaceae family (14 on Bloomipedia; most observed first): Western blue-eyed grass, Blue pigroot, Grasswidow.

More Louisiana flowers

Blue pigroot (Sisyrinchium micranthum)

Blue pigroot

Sisyrinchium micranthum

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White clover (Trifolium repens)

White clover

Trifolium repens

Introduced

🌼 Blooms in LA: February–April
American black elderberry (Sambucus canadensis)

American black elderberry

Sambucus canadensis

Native

🌼 Blooms in LA: May–June

Sources