- Centaurea stoebe ssp. micranthos is an herbaceous biennial or perennial plant that readily invades open areas. Its name is derived from the black margins of the flower bract tips which give the flower heads a spotted look.
- A basal rosette of deeply lobed leaves is produced the first year. Rosette leaves are deeply lobed, petiolate, and approximately 8 in. (20 cm) long. Flowering stems are 1-4 ft. (0.3-1.2 m) tall and branched. Stem leaves are alternate and may be slightly lobed or linear. Leaves become smaller and less lobed toward the apex.
- The small purple to pink flowers bloom in the early summer.
- Mature seeds are shiny black and produced in erect, slender green pods which turn pale brown when mature. The copious seeds are distributed by the wind and contaminated hay.
- Ecological Threat
- Centaurea stoebe ssp. micranthos invades a wide variety of habitats including pastures, open forests, prairies, meadows, old fields, and disturbed areas. It displaces native vegetation and reduces the forage potential for wildlife and livestock. It is native to Europe and western Asia. It was accidentally introduced into North America in contaminated alfalfa and clover seed in the late 1800s.
- Program Aid - USDA APHIS PPQ
- Biology and Biological Control of Knapweed - USDA Forest Service
- Biological Control of Invasive Plants in the Eastern United States - USDA Forest Service
- Invasive Plant Atlas of New England - University of Connecticut
- Weeds Gone Wild: Alien Plant Invaders of Natural Areas - Plant Conservation Alliance
- Element Stewardship Abstract - The Nature Conservancy
- Fire Effects Information System - USDA Forest Service
- Know Your Knapweeds - North Dakota State University
- Weed of the Week - USDA Forest Service
- Weed Field Guide - USDA Forest Service
- Plant Invaders of Mid-Atlantic Natural Areas - National Park Service and U.S. Fish and Wildlife Service
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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
- Arizona Noxious Weeds
- California Invasive Plant Council
- California Noxious Weeds
- City of Ann Arbor Michigan Parks and Recreation
- Colorado Noxious Weeds
- Connecticut Department of Environmental Protection
- Connecticut Invasive Plant Working Group
- EDDMapS Ontario
- Faith Campbell, 1998
- 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.
- Illinois Invasive Plant List
- Invasive Plant Council of New York State
- 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 - Significant Threat
- Maryland Cooperative Extension Service. 2003. Invasive Plant Control in Maryland. Home and Garden Information Center, Home and Garden Mimeo HG88. 4 pp.
- Maryland Department of Natural Resources, 1994
- Massachusetts Noxious Weeds
- Michigan Noxious Weeds
- Mid-Atlantic Exotic Pest Plant Council, 2005
- Montana Noxious Weeds
- National Wildlife Refuge Association, Silent Invasion: A Call to Action from the National Wildlife Refuge Association, 2002. Washington DC. 17 pp.
- Nebraska Noxious Weeds
- Nevada Noxious Weeds
- New Hampshire Prohibited Invasive Species
- New Jersey Department of Agriculture, Division of Plant Industry, 2004
- New Mexico Noxious Weeds
- Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
- North Dakota Noxious Weeds
- Oregon Noxious Weeds
- Pacific Northwest Exotic Pest Plant Council, 1998
- Pennypack Ecological Restoration Trust, Pennsylvania.
- South Carolina Exotic Pest Plant Council - Severe Threat
- South Dakota Noxious Weeds
- Tennessee Exotic Pest Plant Council
- Utah Noxious Weeds
- Virginia Invasive Plant Species List
- Washington Noxious Weeds
- WeedUS - Database of Plants Invading Natural Areas in the United States
- Wisconsin's Invasive Species Identification, Classification and Control Rule
- Wyoming Noxious Weeds
|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.|