- Iris pseudacorus is a herbaceous perennial that can grow up to 3-4 ft. (0.9-1.2 m) in height.
- Broad, sword-shaped leaves are stiff, erect and glaucous. They measure between 1.6-3.3 ft. (0.5-1 m) long and 0.4-1.2 in. (1-3 cm) wide. Rhizomes are pink-fleshed and 0.4-1.6 in. (1-4 cm) in diameter.
- Flowers are showy and bloom from April to June. Usually yellow, their color can range from nearly white to cream. Flowers are 2.75-3.5 in. (7-9 cm) wide. They are borne on erect peduncles with several flowers per stem. There are six perianth clawed segments. Three of these are upward-pointing petals and three are down-ward spreading sepals. Sepals often have purple, brown or red veins on their yellow surface.
- Fruits are 1.6-2.7 in. (4-8 cm) long capsules. The capsules are 6-angled and cylindric-prismatic to ellipsoid. The average capsule contains about 120 white seeds that harden and turn brown as they mature.
- Ecological Threat
- It forms large clonal colonies displacing native species. The rhizomes are able to survive heavy droughts. Rhizomes and seeds can be transported downstream, further spreading the plant. Seeds can germinate even after a wetland area burns. It contains glycosides, making it toxic to grazing animals. No birds are known to disperse the seeds of this plant. Caution should be used when hand-pulling, as it can cause skin irritation.
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EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org
State Invasive List - This map identifies those states that list this species on their invasive species list. For more information, visit Invasive.org
Invasive Listing Sources
- California Invasive Plant Council
- Colorado Noxious Weeds
- Connecticut Department of Environmental Protection
- Connecticut Invasive Plant List
- Delaware Natural Resources and Environmental Control, 2004
- EDDMapS Ontario
- Faith Campbell, 1998
- Great Lakes Early Detection Network
- Hoffman, R. & K. Kearns, Eds. 1997. Wisconsin manual of control recommendations for ecologically invasive plants. Wisconsin Dept. Natural Resources, Bureau of Endangered Resources. Madison, Wisconsin. 102pp.
- Idaho Noxious Weeds
- Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
- John Randall, The Nature Conservancy, Survey of TNC Preserves, 1995.
- Maryland Department of Natural Resources, 1994
- Massachusetts Noxious Weeds
- Mid-Atlantic Exotic Pest Plant Council, 2005
- Montana Noxious Weeds
- Native Plant Society of Oregon, 2008
- New Hampshire Invasive Species Committee. 2005. Guide to Invasive Upland Plant Species in New Hampshire. New Hampshire Department of Agriculture, Markets and Food Plant Industry Division and New Hampshire Invasive Species Committee.
- New Hampshire Prohibited Aquatic Species
- New Hampshire Prohibited Invasive Species
- Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
- Oregon Noxious Weeds
- Pacific Northwest Exotic Pest Plant Council, 1998
- Tennessee Exotic Pest Plant Council
- Vermont Department of Environmental Conservation
- Virginia Invasive Plant Species List
- Washington Noxious Weeds
- WeedUS - Database of Plants Invading Natural Areas in the United States
Other System LinksPlants: IRPS
NPDN Pest: PCJABBB
NPDN Host: 41032
|Common Name Reference:|| USDA, NRCS. 2010. The PLANTS Database. National Plant Data Center, Baton Rouge, LA, USA.|
|Scientific Name Reference:||USDA, NRCS. 2010. The PLANTS Database. National Plant Data Center, Baton Rouge, LA, USA.|