Photographer: Steve Dewet, Utah State University Source: Bugwood.org Copyright: CC BY 3.0 US
The leaves are oblong, prickly, opposite and large (over 5 inches in length). The purple flowers are cone-shaped flower clusters at the ends of branches. Flowering stems can grow to 7 feet in height. Fruits enclose a single seeds, and they are light brown, hairy and 1/5 inch long.
Teasels in the genus Dipsacus can be very aggressive, making them successful at invading prairies and savannas. What also allows this plant to expand its invasive distribution is that it has no natural enemies, seeds can remain viable for up to two years, and it can quickly form large monocultures, excluding all native vegetation.
Dipsacus fullonum grows as a basal rosette for a minimum of none year. Afterwards it they produces a flowering stalk, and the rosette dies after flowering. Common teasel blooms from June through October, and seeds usually fall within 5 feet of the mother plant. However, some birds and other animals can help disperse the seeds. An average teasel plant can produce over 3000 seeds, and 30-80% of the seeds will germinate. This plant has a thick taproot (can be more than 2 feet) with many fibrous secondary roots.
It was introduced to the United States in the 1800s because the dried flowers were used in wool production by teasing the wool apart. By 1913 it had settled in many northeastern states alongside rights-of-ways and pastures. It was reported in Kansas in 1945, Tennessee in 1956, and Wyoming by 1980. It is now present in 43 states.
U.S. Habitat: Pastures, abandoned fields and lots, forests and areas with perennial grass stands. It prefers sunny habitats, but ranges from dry to wet conditions.
U.S. Present: All states except AK, FL, GA, HI, LA, ND and SC
For a state and county distribution map provided by EDD MapS click here
It can resemble cutleaf teasel Dipsacus laciniatus, but the purple flowers and a basal rosette stage help distinguish it.
Common teasel responds very well to treatment with glyphosate, triclopyr and 2,4-D amine. Researchers have found that prescribed burning in conjunction with herbicide is quite effective for large stands. Mowing and repeated moving are very ineffective management practices because the plant can re-sprout from the root crown. No biological controls that are known are practicable in natural areas.
Bentivegna, D.J. and R.J. Smeda. 2008. Chemical management of cut-leaved teasel (Dipsacus fullonum) in Missouri. Weed Technology 22(3): 502-506.
Gucker, C.L. 2009. Fire Effects Information System. USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.
Judd, William W. 1984. Insects associated with flowering teasel, Dipsacus sylvestris, at Dunnville, Ontario. Proceedings of the Entomological Society of Ontario. 114: 95-98.
Mack, Richard N.; Lonsdale, W. Mark. 2001. Humans as global plant dispersers: getting more than we bargained for. Bioscience. 51(2): 95-102.
Roberts, H. A. 1986. Seed persistence in soil and seasonal emergence in plant species from different habitats. Journal of Applied Ecology. 23(2): 639-656.