yellow flag iris
(yellow flag iris)
Family Name: Iridaceae
plant is 4-6 ft. in height, and are spaced from about 36-48 in.
apart. The plant is the only yellow iris in the United States.
The yellow flag iris has a robust stalk, and the plant has a long
season. (2, 5)
The roots of the yellow flag iris are
10-30 cm long. (5)
The yellow flag iris is a tall plant
with long, dark green, flattened, sword like leaves. The leaves
can grow up to 2.5 cm wide. The leaves also arise usually longer
than the stem. (3, 5)
The size of the flower is 3-4 inches
across, and is yellow. The flower is 8-10 cm in diameter.
has 3 sepals that are backward curving and non bearded. The flower time
from June-August. (3, 5)
The fruit of this weed is oblong
and capsule-like and also usually 2" long. (5)
Methods of Reproduction/Spread:
The plant is slowly spread
and easily contained. It is spread by the wind and water. The wind
catches the seed and blows it into the water and the water carries it
downstream to its new home. (5)
Life Styles/Habits/Life Duration:
Environments Favorable to
Yellow-flag-iris will continue to spread
as long as it is being sold in stores and nuseries, and also it will
move down stream just by
the seeds and plant parts. (8)
Yellow-flag-iris is a fast growing and fast
spreading weed. It creates thickets in water just like cattails.
Native Range/probable entry into N. America:
It is native
to Europe, British Isles, North Africa and the Mediterranean
region; unfortunately yellow flag iris is sold over the internet on
gardening web sites. Yellow-flag iris entered the U.S. from
Canada as an ornmental plant in
the early 1900's. (7)
North Western Montana.
Methods of Control:
One of the most useful ways to control this
plant is to use chopping machines that destroy the bulbs/roots.
There is no
biocontrol for this species at this time. Animals seem to eat
yellow flag iris with their hay and other foods out in the wild.
How to Prevent the Spread:
No data available.
: Yellow flag iris lives along stream beds,
near ponds, and in marshes. (5)
1. "yellow flag iris." Perennials on parade. 3/16/04.
Greenhouse, Inc.. 3/16/04
2. "yellow flag iris." Non-Native Invasive Aquatic Plants in the
States. 3/16/04. Center for Aquatic and Invasive Plants. 3/18/04
3. . "Skye Flora." Yellow Flag. April 7, 2003. Photo @ Carl Farmer.
4. . "Yellow Iris (Yellow Flag)." Connecticut Botanical Society. Feb.
2003. Connecticut Wildflowers. 3/11/04
5. "Wildflowers." enature.com. . National Wildlife Federation.
6. University of Florida Aquatic Weed Management Guide, Vandiver
7. Cody WJ. 1961. Iris pseudacorus L. escaped from
cultivation in Canada. Canadian Field Nat., 75: 139-142.
8. No author found.
9. Falinska K. 1986. Demography of Iris pseudacorus L.
populations in abandoned meadows. Ekol. Polska
Zac & Layne
03/04. Updated By:
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