Appearance
Lysimachia nummularia is an herbaceous, low-growing, perennial plant in the primrose family. The smooth creeping stems branch frequently and can grow up to 2 ft (m) long and 2-4 in (5.1-10.2 cm) tall. It is native to temperate Asia and to Europe.

Foliage
The leaves are opposite, simple, and broadly ovate 0.25-1.5 in (0.6-3.8 cm) long with entire margins. The leaves are obtuse at both ends, resembling coins and giving it the common name, moneywort.

Flowers
This plant often does not flower at all. But when it does the flowers are yellow with small dark red spots. The flowers arise from the leaf axils and have pedicels about 0.25-1.5 in (0.6-3.8 cm) long. It blooms from June to August.

Fruit
Fruit are capsules that contain 1-5 seeds each. The seeds are small.

Ecological Threat
Lysimachia nummularia can be found in a variety of different habitat types; however, it grows most vigorously and poses the biggest threat in moist areas such as wet meadows, swamps, floodplain forests, streams banks, bottoms, ditches, roadsides, and along the banks of small water bodies. It can form a mat-like growth capable of excluding more desirable native plant species. It is now found across the United States and Canada.

Resources

• Weed of the Week - USDA Forest Service

Selected Images

Maps

Invasive Listing Sources

• City of Ann Arbor Michigan Parks and Recreation
• Connecticut Invasive Plant Working Group
• Delaware Invasive Species Council
• 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.
• Indiana Invasive Species Council - Invasive Plant List
• Invasive Plant Association of Wisconsin
• Invasive Plant Species of West Virginia
• 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.
• Kentucky Exotic Pest Plant Council - Severe Threat
• Massachusetts Invasive Plants Advisory Group List
• Massachusetts Noxious Weeds
• Massachusetts Prohibited Plant List
• Mid-Atlantic Field Guide to Aquatic Invasive Species
• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• 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 Invasive Species
• Non-Native Invasive Plants of Arlington County, Virginia
• Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
• Ontario’s Invading Species Awareness Program Tracked Species List
• Pennsylvania Department of Conservation and Natural Resources Invasive Plants
• Rhode Island Natural History Survey
• South Carolina Invasive Pest Council
• To be proposed for MISC
• Virginia Invasive Plant Species List
• WeedUS - Database of Plants Invading Natural Areas in the United States
• West Virginia Invasive Species Strategic Plan and Volunteer Guidelines 2014
• West Virginia Native Plant Society, Flora West Virginia Project, and West Virginia Curatorial Database System, September 3, 1999
• Wisconsin Noxious Weeds
• Wisconsin's Invasive species rule – NR 40

References