Dipsacus fullonum L.

Dipsacus fullonum L.
Common Teasel, Fuller's Teasel

Category
Forb/Herb

Description

Height

Fuller’s Teasel forms a basal rosette that grows for a minimum of one year before sending up a tall, branching flowering stalk that can reach to 6 or more feet (2m).

Stem

Stems are erect, stiff, stout, angled and coarsely prickly (increasingly so above).

Leaves

Basal rosette leaves vary from somewhat ovoid in young plants to large, oblong, hairy leaves in older rosettes. Flowering stalks have large, oblong, opposite, sessile leaves that form cups around the stem and grow to 1 foot (3 dm) in length. Leaf margins are toothed to entire and ± prickly, especially on the midrib beneath.

Flowers

Numerous small flowers, each with lilac to lavender tubular corollas, are packed into dense ±cylindric (egg-shaped) terminal spikes that are 1-4 inches (4-10 cm) long, and subtended by long, upward-curving, narrow, pointed bracts that normally exceed the height of the inflorescence. Blooming generally occurs from June to October.

Fruit

Achenes are linear, (3-4 mm) long, pubescent, grayish brown, truncate at the apex, and 4-angled with longitudinal ridges.

Images

Photo: David Cappaert, Michigan State University, Bugwood.org
More images of Dipsacus fullonum

Life History

uller’s teasel, also called common teasel, is a member of the Dipsacaceae (Teasel) family. It is a monocarpic perennial (i.e. a plant that grows a basal rosette for a minimum of one year then sends up a flower stalk and dies after flowering). A single plant can produce over 2,000 seeds. Seeds remain viable for at least two years and have a germination rate of 30-80%, depending on conditions. Because seeds do not disperse far naturally, most seedlings are located near parent plants, where they take advantage of the bare ground formerly occupied by teasel rosettes. Seeds can be further spread by water, mowing and other agricultural equipment, or improper disposal of dried seed heads from flower arrangements.

Habitat

Fuller’s Teasel prefers moist, low, sunny, open areas. It most commonly occurs in pastures, old fields, roadsides, waste places and other heavily disturbed sites; however, it sometimes occurs in high quality prairies, savannas, seeps, and sedge meadows.

Origin and Distribution

Fuller’s Teasel is endemic to Europe and was introduced to North America as early as the 1700’s for use in the textile industry for raising the nap (drawing out the ends of fibers) of woolen and cotton fabric. It is likely that it was also introduced accidentally from other plant materials imported from Europe. Teasel is sometimes used as a horticultural plant and has been used extensively in the floral industry in dried flower arrangements. It is now widespread in North America, having been recorded in British Columbia, Ontario, and Quebec in Canada and 42 of the 48 contiguous United States. It is listed as a noxious weed in CO, IA, MO, NM.

Bibliography

Bryson, C.T. and M.S. DeFelice, eds. Weeds of the South. 2009. University of Georgia Press, Athens. 468 pp.

Kaufman, S.R. and W. Kaufman. 2007. Invasive plants: guide to identification and the impacts and control of common North American Species. Stackpole Books, Mechanicsburg, PA. 458 pp.

Missouri Department of Conservation. 2010. Field guide: common teasel (Dipsacus fullonum). http://mdc.mo.gov/discover-nature/field-guide/common-teasel (accessed December 28, 2010).

Wisconsin Department of Natural Resources. 2010. Common teasel (Dipsacus fullonum subsp. sylvestris). http://dnr.wi.gov/invasives/fact/teaselcom.htm (accessed December 28, 2010).

USDA, NRCS. 2010. The Plant Database, PLANTS profile for Dipsacus fullonum (Fuller’s teasel). National Plant Data Center, Baton Rouge, LA http://plans.usda.gov (accessed December 28, 2010).

Management Recommendations

Mechanical Controls

Hand Pulling: Very small seedlings can be pulled by hand when the soil is moist and young rosettes can effectively be dug up using a dandelion digger or similar tool. Care should be taken to remove as much of the tap root as possible. Once rosettes get large, it becomes more difficult to dig roots without damaging the area around the plant. At this stage, it is advisable to either apply herbicide (see Herbicidal Control below), or wait until the initiation of flowering, then remove flowering heads before seed set. Flowering heads should be removed from the site as immature seed heads left in place may still develop some viable seeds. Cutting off the flowering stalks just at flowering time will usually prevent resprouting from the root crown. Cutting flowering stalks prior to flowering should be avoided since the plants will resprout and flower again. A later inspection should be performed to catch any root crowns that do resprout.

Mowing: Use of mowing to control teasel can be challenging. Even with repeated mowing, it is difficult to eliminate teasel. Plants that were knocked down but not cut during a previous mowing event can lie horizontally and still produce seed. These plants, and those that do get cut but resprout near the ground level, often occur too low to the ground to be reached by the mower.

Prescribed Burning: Late spring burns can be useful in controlling teasel before it becomes dense. Burning should be employed with other methods to insure maximum control. Manual removal is assisted by burning the site in the spring so that the basal rosettes are visible amidst the blackened soil and grasses.

Herbicidal Controls

Foliar Spray Method: When mechanical control is not feasible, or is inadvisable, foliar applied herbicides can be used as a cost-effective alternative. Triclopyr and glyphosate have both been used successfully to control teasel.

Triclopyr -- Apply a 2% solution of triclopyr and water plus a non-ionic surfactant, using a tank or backpack sprayer to thoroughly cover all leaves. Do not apply so heavily that herbicide drips off the leaf surface. Triclopyr should be applied during the growing season, preferably before the plant has bolted (sent up a flowering stalk). Applications can be made after bolting, but there is a risk that seeds may still develop, depending upon the date of application. NOTE: Triclopyr is a dicot-selective herbicide and should not harm monocots (grasses and similar species); however, use extra caution to avoid getting chemical spray on any non-target species.

Glyphosate -- Apply a 2% solution of glyphosate and water plus a non-ionic surfactant, using a tank or backpack sprayer to thoroughly cover all leaves. Do not apply so heavily that herbicide drips off the leaf surface. Glyphosate should be applied during the growing season, preferably before the plant has bolted. Applications can be made after bolting, but, as with later applications of triclopyr, there is still a risk that seeds can develop, depending upon the date of application. NOTE: Glyphosate is a non-selective herbicide (i.e. it kills any green plant). Use extra caution to avoid getting chemical spray on any non-target species. Refer to manufacturer’s label for specific information and restrictions regarding use.

NOTE: Because Fuller’s teasel often grows in wet areas, extra precautions should be made to protect nearby water sources. Some wet sites require herbicides that are labeled specifically for use near water. Triclopyr, under the trade name “Garlon 3A”, and glyphosate, under the trade name “Accord”, are examples of herbicides approved for use near water. The addition of certain types of surfactants to herbicide mixtures can also be detrimental to aquatic species in nearby water. Be sure to refer to manufacturer’s label for specific information and restrictions regarding use.