Iris douglasiana Herb.
Douglas Iris, Mountain Iris, Western Iris
Iridaceae (Iris Family)
Synonym(s): Iris douglasiana var. major, Iris douglasiana var. oregonensis
USDA Symbol: IRDO
The rhizomes of Mountain iris or Douglas iris spread slowly, eventually creating a 2-4 ft. wide clump. Tufts of 1-2 ft., sword-shaped, dark-evergreen leaves arise from the rhizome and surround a flowering stalk of equal height. Several showy iris blossoms emerge from leafy bracts atop the stalks. The flowers are usually blue, though the colors can range from pale cream to yellow to reddish purple. Large, reddish-purple, pinkish, white, or cream flowers, with lilac veins, on stout branched stalks rising from clumps of sword-shaped leaves.
This is a common iris in the Redwood region. The genus name, Greek for rainbow, refers to the variegated coloration of the flower. In Greek mythology, Iris, a member of Heras court and goddess of the rainbow, so impressed Hera with her purity that she was commemorated with a flower that blooms in the rainbow colors of her robe.
From the Image Gallery
Bloom InformationBloom Color: Blue
Bloom Time: Mar , Apr , May
DistributionUSA: CA , OR
Native Distribution: Coastal region from Santa Barbara Co., CA to Coos Co., OR
Native Habitat: Grassy slopes; open woods
Growing ConditionsLight Requirement: Part Shade
Soil Moisture: Moist
Soil pH: Acidic (pH<6.8)
Soil Description: Moist to dry, nutrient-rich soils.
Conditions Comments: Douglas iris is a vigorous, shade and drought tolerant iris. Crosses with I. innominata and other West Coast species are collectively called Pacific Coast hybrids.
BenefitConspicuous Flowers: yes
PropagationDescription: Increase by seed or rhizome divisions. Divide rhizomes in late fall or early spring but cutting the leaves back to about 5 in. and then cutting between the tufted clumps. Plant fresh seeds in early fall in permanent location or flats that are left out o
Seed Collection: Easily collected from the large capsules.
Seed Treatment: No pretreatment is necessary, although a moist stratification (3 mo. at 40 degrees) may be beneficial.
Commercially Avail: yes
Find Seed or Plants
Find seed sources for this species at the Native Seed Network.
View propagation protocol from Native Plants Network.
From the National Organizations DirectoryAccording to the species list provided by Affiliate Organizations, this plant is on display at the following locations:
Santa Barbara Botanic Garden - Santa Barbara, CA
Native Seed Network - Corvallis, OR
BibliographyBibref 995 - Native Landscaping from El Paso to L.A. (2000) Wasowski, S. and A. Wasowski
Search More Titles in Bibliography
From the ArchiveWildflower Newsletter 1984 VOL. 1, NO.4 - Lady Bird Heartened by Progress, Horticultural Society Annual Meeting Held, Dire...
Additional resourcesUSDA: Find Iris douglasiana in USDA Plants
FNA: Find Iris douglasiana in the Flora of North America (if available)
Google: Search Google for Iris douglasiana
MetadataRecord Modified: 2009-02-21
Research By: TWC Staff