Iris pseudacorus (Pale-yellow Iris)

Plant Info
Also known as: Yellow Flag
Family:Iridaceae (Iris)
Life cycle:perennial
  • Invasive - ERADICATE!
Habitat:part shade, sun; marshes, along shores
Bloom season:May - June
Plant height:2 to 4 feet
Wetland Indicator Status:GP: OBL MW: OBL NCNE: OBL
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

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Detailed Information

Flower: Flower shape: 3-petals

[photo of flower] Flower is 3 to 4 inches across with 3 large petal-like sepals that hang down and 3 smaller upright petals. The lower sepals have a ring of reddish brown flecks near the base and are beardless. There are a few flowers at the end of each stalk.

Leaves: Leaf attachment: basal Leaf type: simple

[photo of leaves] Leaves are long and sword-like, about 1 inch wide and 3 to 4 feet long with a pointed tip. A group of leaves fans out from the base of the plant. The leaves are mostly longer than the flower stalk.

Fruit: Fruit type: capsule/pod

[photo of developing fruit] Fruit is an oblong, 3 angled capsule around 2 to 3 inches long and 1/3 to ½ as wide.


Pale-yellow Iris is an invasive species in Minnesota, escaping cultivation and potentially forming large colonies along shores and in shallow waters.

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More photos

Photos by K. Chayka taken at Long Lake Regional Park, Ramsey County.


Have you seen this plant in Minnesota, or have any other comments about it?

Posted by: Suzy - Fillmore County
on: 2011-06-04 17:17:38

There are literally hundreds of the in my yard. The line the spring that feeds in to the south fork of the root river.

Posted by: troy - maple grove
on: 2012-02-29 10:42:39

Ive seen this at Elm Creek Park Reserve, pretty Iris, actually would like some on my property. I see no comments on this, are people loving all Iris and not caring to post comments here? The Iris Ive witnesses in MN are slow to spread and maybe not that big of a control problem, maybe Im wrong. Anyone please feel free to reply!!

Posted by: Robin - Northwood Park, New Hope, MN.
on: 2012-05-25 18:36:47

There are just a few that are in bloom now along the lake shore near the playground.

Posted by: Krista - Franconia
on: 2013-06-19 22:24:39

Saw several clusters of them while kayaking down the St Croix between Franconia and Osceola on June 16th.

Posted by: gary - Carlton County
on: 2019-05-14 20:04:00

I saw it a few years go in a drainage ditch between HWY 61 and the Carlton County Fairgrounds in Barnum.

Posted by: Travis - Minneapolis
on: 2021-06-06 21:40:43

Currently three separate clumps flowering on the south and south western edges of Bde Maka Ska (lake calhoun).

Posted by: HvHughes - NW Polk County
on: 2023-06-17 13:23:03

Spotted it June 17, 2023. what do you recommend to use to eradicate it?

Posted by: K Chayka
on: 2023-06-17 17:00:25

HvHughes, the DNR includes some control info on their yellow iris species page.

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