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 Appearance:
Perennial forb, 2-3 1/2' tall; erect, branching, smooth stems
growing from a deep vertical root. Stems, flowers, and leaves emit
a white milky sap when broken that can burn skin. Leaves:
Alternate, small, oblong to lance-shaped,
on the upper part of stem; scale-like on the lower part of the stem.
Flower:
Small, borne by showy yellow-green bracts which open in late May;
flowers bloom June into fall. Umbel-like cluster of 7-10 flowers at
the top of each stem; single, stemmed flowers grow from leaf axils
below. Seed:
Explosive dispersal from a seed capsule up to 15 feet; high germination
rate; seeds remain viable in the soil for 7 years. Roots:
Extensive deep root system, vegetative reproduction from crown and
root buds. |
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Rapidly invades primarily
non-cropland disturbed environments. Is a threat mainly to mesic
and dry prairies and savannas, quickly displacing native plants.
Tolerant of a wide range of habitats, from dry to moist, and sunny
to semishade. Most aggressive in dry soil conditions where there
is less competition from native plants. Native to Europe and Asia
it occurs across much of the northern U.S. in the grasslands and
savannas of the Great Plains.
Legal Status:
This plant is a prohibited noxious weed in Minnesota and must be
controlled or eradicated as required by Minnesota Statutes, section
18.78.
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 Wisconsin
Manual of Control Recommendations for Ecologically Invasive Plants,
1997.
Plant Conservation Alliance: Alien Plant Working Group www.nps.gov/plants/alien/fact
The Nature Conservancy Element Stewardship Abstract
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