western blue iris (Rocky Mountain iris)
Iridaceae (Iris family)
Introduction to Vascular Plants
Photograph
© Thayne Tuason (Photo ID #76371)
Species Information
General:
Perennial herb from a thick rhizome; flowering stems usually simple, sometimes branched, 20-50 cm tall.
Leaves:
Mostly basal, linear-lanceolate, 20-50 cm long, 5-10 mm wide, entire, the tips long-pointed.
Flowers:
Inflorescence of 1 or 2, sometimes 3 or 4, showy flowers on stout, 4- to 6-cm long stalks; flowers light to deep blue, purple-lined, the tubes flared above, less than 6 mm long, the bracts green or reddish and not papery at flowering; petals erect, 3-6 cm long, 1.5-2 cm wide; sepals oblanceolate, 5-6 cm long, about 1 cm wide, bent back; style branches 2-2.5 cm long, the crests less than 1/2 as long; stigmas 2-lobed.
Fruits:
Capsules, cylindrical, 3-5 cm long; seeds numerous.
Illustration
If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.
Illustration Source: The Illustrated Flora of British Columbia
USDA Species Characteristics
Flower Colour:
Purple
Blooming Period:
Spring
Fruit/Seed characteristics:
Colour: Black
Present from Summer to Spring
Source: The USDA
Habitat and Range
Moist lake margins and marshy meadows in the lowland and montane zones; rare in W BC, known from scattered localities, where probably introduced; E to SE AB and S to MN, NE, NM, AZ, CA and N MX.Taxonomic Keys
1. Flowers yellow; plants usually more than 1 m tall.................Iris pseudacorus
1. Flowers predominantly blue, purple, or white; plants usually less than 1 m tall. 2. Principle leaves usually more than 1 cm wide; petals (standards) 0.5-2 cm long, sharp-pointed; plants occurring N of 60 degrees N, also SE AK and YK........Iris setosa 2 Principle leaves 1 cm wide, or less; petals (standards) 3-6 cm long, blunt-tipped; plants occurring in S BC 3. Blades of sepals (falls) oblanceolate; bracts green or reddish and not papery at flowering time............Iris missouriensis 3. Blades of sepals (falls) broadly rounded; bracts brown and papery at flowering time...............Iris sibirica Source: The Illustrated Flora of British Columbia |