common tansy
Tanacetum vulgare L.

Overview

Appearance

Tanacetum vulgare is an aromatic, perennial herbaceous plant that can reach up to 5 ft. (1.5 m) in height.

Foliage

The leaves of T. vulgare are alternate and sessile or with a short-stalked. The leaves are highly divided and dotted with small glands.

Flowers

The yellow, button-like flowers develop in dense flat-topped clusters at the apex of the plant. T. vulgare flowers bloom from August to October.

Fruit

The fruits are 5-angled achenes with small glands. Each plant is capable of producing over 50,000 seeds per year.

Ecological Threat

T. vulgare invades disturbed areas, ditch banks and riparian areas. It is native to temperate Asia and Europe. T. vulgare can be toxic if animals or people ingest large amounts of it.

Resources

• Weed of the Week - USDA Forest Service

Selected Images

Maps

Invasive Listing Sources

• Alberta Weed Control Act
• California Invasive Plant Council
• Colorado Noxious Weeds
• Invasive Plant Association of Wisconsin
• 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.
• Minnesota Noxious Weeds
• Montana Noxious Weeds
• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• New Hampshire Invasive Plant Species Watch List
• Pacific Northwest Exotic Pest Plant Council, 1998
• Washington Noxious Weeds
• WeedUS - Database of Plants Invading Natural Areas in the United States
• Wisconsin Noxious Weeds
• Wisconsin's Invasive species rule – NR 40
• Wyoming Noxious Weeds

References