Taxonomic name: Tussilago farfara L.
Common names: assfoot (English), British tobacco (English), bull's-foot (English), clayweed (English), cleats (English), colt-herb (English), coltsfoot (English), coughwort (English), dove-dock (English), dummyweed (English), Foalfoot (English), ginger (English), gingerroot (English), gowan (English), hoofs (English), horsefoot (English), horsehoof (English), kuan dong (English), pas- d'âne (French-Canada), sowfoot (English), tussilage
(English-Canada), tussilage pas-d'âne (French-Canada)
Organism type: herb
Tussilago farfara is a perennial herb which spreads mainly through underground rhizomes. During the summer, food is stored in the rhizomes for the following year's early spring growth. Tussilago farfara thrives on gravelly soil and along roadsides. There are management strategies available to combat Tussilago farfara, but if left unchecked it can take over an entire field. It is best to stop Tussilago farfara before it spreads as controlling it once it has become established is difficult. It is believed that Tussilago farfara has some medical benefits.
Harvey Wright (1997) states that Tussilago farfara "is a low growing perennial plant. It has large, deep green leaves, somewhat similar in size and shape when fully grown to those of velvetleaf or cocklebur. The plant has no main stem, however. The leaf petiole holds the leaves 10 to 20cm above the soil, often forming a complete canopy covering the soil. The top leaf surface has a smooth, almost waxy appearance, while the underside of the leaf is covered with white wool-like hairs. Usually leaf stems and larger leaf veins are distinctly purple in colour."
Arctium lappa, Taraxacum officinale
agricultural areas, natural forests, ruderal/disturbed, urban areas, water courses
Wright (1997) states that T. farfara "has the ability to thrive on gravelly soils, and is a common weed in gravel pits." Sievers (1930) goes on to state that T. farfara "is found along brooks and in wet places and moist clayey soil along roadsides from eastern Quebec to Pennsylvania, Ohio, and Minnesota." The species also occurs in urban areas, agricultural areas often on roadsides and pastures and in open forests, in its natural range, (Elven, 1994).
Wright (1997) states that, "when gravel from infested pits is used in roadbed maintenance, some rhizomes of Tussilago farfara survive, and start up new Tussilago farfara patches. Tussilago farfara seems to compete strongly with the roadside grasses and is not controlled by commonly used roadside herbicides. Eventually the patch may expand to creep under the fence and into an adjoining cultivated field. Tillage operations can then spread the weed throughout the field. Seed blown by the wind may also start new patches, depending on the herbicide programme being used on the field where the seed germinates. In field crops, Tussilago farfara has been reported in corn, soybeans, winter wheat, spring grain and alfalfa stands. Once well-established, Tussilago farfara appears to hold its own against competition from these crops. If not controlled, Tussilago farfara can, in time, take over a field."
Reed (2002) states that T. farfara "has been used since pre history to relieve coughs and other respiratory problems. It is made into herbal teas (un-opened flowers and leaves) and is found in commercial cough preparations. It is an ingredient in concoctions used to treat diarrhea. The leaves are sometimes smoked for relief of congestion. The crushed leaves or a leaf decoction is used externally where it may be applied to sores, injuries, rashes and painful joints. The large mucilage content accounts for most of the medical benefit derived from the plant."
Namura-Ochalska-Anna (1993) reports that the success of Tussilago farfara L. in colonizing disturbed environments, after its seeds reach the site and germinate, is a function of several of the important traits of this species: 1) tolerance of seedlings and juveniles to a wide range of changeable external conditions, 2) fast growth and development of individuals, 3) a high degree of adaptability in reaching successive stages of development, 4) guerilla type growth, 5) intense spreading and renewal of individuals of generative and vegetative origin, 6) high effectiveness of vegetative reproduction, 7) adaptable allocation of resources to above-, and underground shoots.
Native range: According to Hultén & Fries (1986), the native range of Tussilago farfara is mainly Europe and adjacent Asia. Its distribution becomes more scattered (or less well known) going east in Asia, and in Africa it is only found in a few areas in the north-western corner.
Known introduced range: Its known introduced range covers north-eastern US and eastern Canada.
Introduction pathways to new locations
Agriculture: Wright (1997) states that, "Eventually the patch may expand to creep under the fence and into an adjoining cultivated field. Tillage operations can then spread the weed throughout the field."
Transportation of habitat material: Wright (1997) states that, "when gravel from infested pits is used in roadbed maintenance, some rhizomes of T. farfara survive, and start up new T. farfara patches.
Local dispersal methods
Agriculture (local): Wright (1997) states that, "Eventually the patch may expand to creep under the fence and into an adjoining cultivated field. Tillage operations can then spread the weed throughout the field."
On animals (local): Wright (1997) states that, "Seed blown by the wind may also start new patches, depending on the herbicide program being used on the field where the seed germinates."
Transportation of habitat material (local): Wright (1997) states that, "when gravel from infested pits is used in roadbed maintenance, some rhizomes of T. farfara survive, and start up new T. farfara patches.
Chemical: Wright (1997) states that for Tussilago farfara, "roundup has been used for the non-selective control of T. farfara and has often given good control. Poor control has usually been due to herbicide application too early in the season. T. farfara foliage is slow to develop in the spring, particularly if the field has been worked and planted to a crop. Leaves may not be fully developed until late June or mid-July. Application of Roundup at an earlier stage will kill all foliage, but not eradicate the rhizomes. Any affected forage in the treated spots cannot be harvested until treated plants turn brown. To date, most T. farfara occurs in only a few patches in a field. If the weed has been well distributed in a field by tillage operations, it may be necessary to apply an overall spray in a non-crop situation. The best approach to T. farfara control is to stop its spread when only a few patches are present and before it becomes a serious problem throughout the field or farm."
Wright (1997) states that T. farfara "spreads by underground rhizomes, which develop mainly in the plow layer (5 to 20cm deep). These rhizomes produce quite dense stands of above-ground foliage. It is common to find only 2 or 3 patches of T. farfara in a field, with patches gradually expanding outward due to rhizome growth. These patches usually range from 3 to 6 metres in diameter. T. farfara has a very unique flowering characteristic. The bright yellow flowers, similar to dandelions but slightly smaller, appear early in the spring, before any leaves emerge. In Southern Ontario, T. farfara flowers in April, often before the last of the snow banks have melted. Flower heads have even been known to push through snow. The white, fluffy seed heads also resemble those of dandelions. However, T. farfara seed will mature by the time the very first dandelions are coming into bloom. T. farfara is not a prolific seed producer compared to many annual weeds". Each flower head produces only a few hundred seeds, (Skarpaas, O., pers.comm, 2004)
Wright (1997) states that, "As the seed on earlier flowers of Tussilago farfara ripens, the Tussilago farfara leaves finally begin to emerge above ground. Leaves will continue to grow in number and size for several weeks, so that the canopy does not reach full density until late June to mid-July. During the summer, food is stored in the rhizomes for the following year's early spring growth."
Reviewed by: Olav Skarpaas Postdoc scholar, Department of Biology The Pennsylvania State University. USA.
Compiled by: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)
Last Modified: Wednesday, 16 November 2005