Burke: Iris pseudacorus vs. Iris foetidissima

	Iris pseudacorus	Iris foetidissima
	pale yellow iris	stinking iris
Habit	Herbaceous perennial from short, thick rhizomes, forming dense clumps, the simple flowering stem up to 1 m. tall, leafy.
Leaves	Basal leaves stiff, narrowly linear, 5-9 dm. long and 10-15 mm. broad; cauline leaves reduced upward.
Flowers	Inflorescence branched, few to several flowered, 1.5-5 dm. long; flowers pale to deep yellow, purple-lined; pedicles up to 5 cm. long; perianth parts fused in a tube at the base, the tube about about 12 mm. long; sepals 3, obovate, spreading, about 5 cm. long; petals 3, much shorter and narrower than the sepals, upright; stamens 3, opposite the sepals; style branches 3, about 22 mm. long, with 2 terminal lobes less than as long; stigma triangular; ovary inferior.
Fruits	Capsule 3-celled, leathery, 5-8 cm. long.

	Iris pseudacorus	Iris foetidissima
Flowering time	May-July	May-June
Habitat	Wetlands, lake and pond margins, irrigation ditches, backwaters, and other wet places where often disturbed; invasive.	Fields, forest edge, and other disturbed areas at low elevations.
Distribution	Occurring on both sides of the Cascades crest in Washington, but more common west of the crest; British Columbia to California, east to Idaho and Montana; also in eastern North America. [WildflowerSearch map] [BONAP county map]	Occurring west of the Cascades crest in lowland western Washington; also in southwestern British Columbia and California. [WildflowerSearch map] [BONAP county map]
Origin	Introduced from Eurasia	Introduced from Europe
Conservation status	Not of concern	Not of concern
Sibling taxa	I. foetidissima, I. germanica, I. missouriensis, I. tenax	I. germanica, I. missouriensis, I. pseudacorus, I. tenax
Web links	Local floras: BC, 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	Local floras: CA, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Iris pseudacorus

Iris foetidissima

pale yellow iris

stinking iris

Habit

Herbaceous perennial from short, thick rhizomes, forming dense clumps, the simple flowering stem up to 1 m. tall, leafy.

Leaves

Basal leaves stiff, narrowly linear, 5-9 dm. long and 10-15 mm. broad;

cauline leaves reduced upward.

Flowers

Inflorescence branched, few to several flowered, 1.5-5 dm. long;

flowers pale to deep yellow, purple-lined; pedicles up to 5 cm. long;

perianth parts fused in a tube at the base, the tube about about 12 mm. long;

sepals 3, obovate, spreading, about 5 cm. long;

petals 3, much shorter and narrower than the sepals, upright;

stamens 3, opposite the sepals;

style branches 3, about 22 mm. long, with 2 terminal lobes less than as long;

stigma triangular;

ovary inferior.

Fruits

Capsule 3-celled, leathery, 5-8 cm. long.

Iris pseudacorus

Iris foetidissima

Flowering time

May-July

May-June

Habitat

Wetlands, lake and pond margins, irrigation ditches, backwaters, and other wet places where often disturbed; invasive.

Fields, forest edge, and other disturbed areas at low elevations.

Distribution

Occurring on both sides of the Cascades crest in Washington, but more common west of the crest; British Columbia to California, east to Idaho and Montana; also in eastern North America.

[WildflowerSearch map]

[BONAP county map]