OregonFlora: Iris missouriensis

	Iris missouriensis
	Rocky Mountain iris, western blue flag
Habit	Herbs to 60 cm tall.
Roots	fleshy; rhizomes freely branching; stout, covered with old leaf bases.
Stems	unbranched or up to 2-branched.
Leaves	basal leaves light green, usually white basally or sometimes purplish, 3–12 mm wide, glaucous; cauline leaves similar to basal.
Inflorescences	2–3-flowered; bracts keeled; outer usually shorter than inner.
Flowers	perianth blue, lavender, or white, veined deeper violet; sepals deeply veined lilac-purple, with yellow-white signal at base of limb; claws yellowish white, veined and dotted with purple; floral tube less than 12 mm; style tips rounded; margins irregularly toothed; stigmas 2-lobed.
Fruits	round in cross section, with 6 ridges.
Seeds	globular to pear-shaped, light brown, wrinkled.
2n	=38.

	Iris missouriensis
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	Wet meadows, roadside ditches, margins of streams. Flowering May–Jul. 300–2000 m. BR, BW, Col, ECas, Lava, Owy. CA, ID, NV, WA; north to British Columbia, northeast to MN and southeast to NM, south to Mexico. Native. The leaves of I. missouriensis are unpalatable to livestock, and the species is considered a noxious weed in pastures. This species is morphologically variable across its large geographic range.
Source	Flora of Oregon, volume 1, page 261 Ann Willyard
Sibling taxa	I. bracteata, I. chrysophylla, I. douglasiana, I. germanica, I. innominata, I. pseudacorus, I. tenax, I. tenuis, I. tenuissima
Web links	Local floras: CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Iris missouriensis

Rocky Mountain iris, western blue flag

Habit

Herbs to 60 cm tall.

Roots

fleshy;

rhizomes freely branching; stout, covered with old leaf bases.

Stems

unbranched or up to 2-branched.

Leaves

basal leaves light green, usually white basally or sometimes purplish, 3–12 mm wide, glaucous;

cauline leaves similar to basal.

Inflorescences

2–3-flowered;

bracts keeled; outer usually shorter than inner.

Flowers

perianth blue, lavender, or white, veined deeper violet;

sepals deeply veined lilac-purple, with yellow-white signal at base of limb;

claws yellowish white, veined and dotted with purple;

floral tube less than 12 mm;

style tips rounded;

margins irregularly toothed;

stigmas 2-lobed.

Fruits

round in cross section, with 6 ridges.

Seeds

globular to pear-shaped, light brown, wrinkled.

=38.

Iris missouriensis

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Wet meadows, roadside ditches, margins of streams. Flowering May–Jul. 300–2000 m. BR, BW, Col, ECas, Lava, Owy. CA, ID, NV, WA; north to British Columbia, northeast to MN and southeast to NM, south to Mexico. Native.

The leaves of I. missouriensis are unpalatable to livestock, and the species is considered a noxious weed in pastures. This species is morphologically variable across its large geographic range.

Source

Flora of Oregon, volume 1, page 261
Ann Willyard

Sibling taxa