: Cut-leaved teasel
: Introduced to North America as early as the 1700s. The first cultivation took place in Onondaga County, New York.
: Biennial; monocarpic; grows 2-6 ft tall; stout taproot; first year plant a basal rosette of wrinkled leaves.
: Stem leaves lance-shaped and irregular, deeply pinnately-cut, opposite, joined at bases surround the stem in a cup-like appearance.
: 3 m tall, with hooked and straight prickles; striate ridged, herbaceous but stout, erect, typically single from the base, branching in the apical half.
: White to purple in color, 4-parted, with irregular petals; inflorescence a dense, cylindrical cluster on a long, naked stalk, spiny bracts not taller than the flower cluster; blooms July through September.
Fruit and seeds
: Each flower is replaced by an oblong seed that is 4-angled, truncate on one end and rounded on the other, plants can produce up to 2000 seeds viable for at least 2 years.
: Native to Europe. Grows in moist soils and found along roadsides and in disturbed areas.
: By seed.
: Fuller's teasel (Dipsacus fullonum
); Wild lettuce (Lactuca spp.
) when in rosette stage, quite different once flowering stalk forms.
Monitoring and rapid response
: Hand-pulling and digging for small infestations; Frequent mowing throughout growing season; effectively controlled using any of several readily available general use herbicides.
: The information provided in this factsheet was gathered from the Minnesota Department of Agriculture and the Robert W. Freckmann Herbarium.
Individual species images that appear with a number in a black box are courtesy of the Bugwood.org network (http://www.invasive.org).Individual photo author credits may not be included due to the small display size of the images and subsequent difficulty of reading the provided text. All other images appear courtesy of Google (http://images.google.com).