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Iris giganticaerulea (Giant blue iris)
Loughmiller, Campbell and Lynn

Iris giganticaerulea

Iris giganticaerulea Small

Giant Blue Iris, Blue Flag

Iridaceae (Iris Family)

Synonym(s): Iris alticristata, Iris aurilinea, Iris citricristata, Iris elephantina, Iris fluviatilis, Iris miraculosa, Iris paludicola, Iris parvicaerulea, Iris rivularis, Iris venulosa, Iris wherryana


USDA Native Status: L48 (N)

The giant blue iris grows 3-5 feet tall and prefers freshwater marshes. The leaves are 30 inches long or less and 1 1/2 inches wide; they clasp the stem near the base. The blue outer tepals, 3 inches long by 1 3/4 inches wide, are marked with a whitish patch with a prominent yellow center; they hang down and are called "falls." The blue, erect inner tepals are 3 inches long and are called "standards."

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. 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
Size Class: 3-6 ft.

Bloom Information

Bloom Color: Blue , Purple
Bloom Time: Mar , Apr


Native Distribution: LA coastal areas
Native Habitat: Fresh water habitats, tolerates brackish water to some extent

Growing Conditions

Light Requirement: Part Shade
Soil Moisture: Wet
Soil Description: Wet, rich soils.
Conditions Comments: Tolerates flooded conditions.


Conspicuous Flowers: yes


Description: Clump division is the usual method of increase. All native iris can be grown from seed.
Seed Collection: Not Available
Seed Treatment: Not Available
Commercially Avail: yes

National Wetland Indicator Status

Status: OBL
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.


Bibref 248 - Texas Wildflowers: A Field Guide (1984) Loughmiller, C. & L. Loughmiller

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Additional resources

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


Record Modified: 2016-04-07
Research By: TWC Staff

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