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Species
Tussilago farfara L.
IUCN
NCBI
EOL Text
More info on this topic.
More info for the terms: cover, density, peat, peatland, reclamation, restoration, shrub, succession, wildfire
Coltsfoot generally achieves its highest densities in disturbed areas and does not persist past early succession. In its North American range, coltsfoot is frequently documented in early-successional plant communities or disturbed areas. Near Quebec City, Quebec, coltsfoot was the most abundant species (2.7% cover) in a boreal peatland 1 year after restoration efforts. Coltsfoot was present in ditches prior to restoration efforts, and rhizomes were left in the ground after a grader disturbed the plants. In postdisturbance year 2, coltsfoot cover had increased, and coltsfoot was the third most abundant (4.9% cover) species; field horsetail (Equisetum arvense) and winter bentgrass (Agrostic hyemalis) were the most abundant [23]. Five years after an ice storm near Montreal, Quebec, mean coltsfoot cover was 0.2% in an old-growth sugar maple-American beech-red oak forest [35]. In Athens County, Ohio, coltsfoot occurred in 7- to 9-year old clearcuts [89]. Coltsfoot dominated some highly disturbed gravel riverbanks in boreal forest in Gros Morne National Park, Newfoundland [80].
Coltsfoot also occurs in early-successional plant communities or disturbed areas in its native range. In England, coltsfoot colonized the "less advanced stages" of fine-structured talus slopes and spoil banks in an abandoned chalk quarry [94]. In the British Isles, coltsfoot occurred on sand dunes where there was abundant bare ground and the soil was too unstable for moss colonization [42]. In Sweden, coltsfoot occurred in young (<10 years old) and old (up to 100 years old) abandoned gravel pits but was most common in young pits with high clay content [9]. In northwestern Czech Republic, coltsfoot often dominated 4- to 10-year-old abandoned basalt quarries where spoils with a high proportion of fine-structured subsoil were dumped [68]. In Hungary, coltsfoot dominated brown coal spoils within 3 years after abandonment [75].
In its native range, coltsfoot generally does not persist past early succession. In an abandoned wheat (Triticum spp.) field in Great Britain, coltsfoot was abundant 4 and 13 years after abandonment but scarce or occasional 21 and 31 years after abandonment. The author noted that coltsfoot looked like it would be "eliminated within the next few years" [15]. On nutrient-poor (low organic carbon and nitrogen) "protosoil" in central Germany, coltsfoot had the third highest cover (approximately 15%) during postdisturbance year 1. Coltsfoot cover subsequently declined, and at the end of the study in postdisturbance year 14, its cover was approximately 2% [82]. Coltsfoot colonized gravel areas in a moraine following a receding glacier in Obergurgl, Austria. It was found within 1,300 feet (400 m) of the glacial snout within 4 years of the start of colonization but was absent by the 19th year [70].
Coltsfoot is considered a "weak competitor" [64]. Coltsfoot cover apparently declines over time with increased vegetation density and cover. After a stand-replacing wildfire on drained peat soils in forested lowlands in the Pra River floodplain, Russia, coltsfoot occurred in mucky depressions where a thick peat layer (>39 inches (100 cm)) had burned to mineral soil and created a 4- to 6-inch (10-15 cm) deep ash horizon. Coltsfoot was present in postfire years 1 to 4 but absent in postfire year 5. Starting in postfire year 4, a continuous plant cover dominated by chee reedgrass (Calamagrostis epigeios) developed, and a humus horizon had formed in the upper soil layer [112], apparently reducing coltsfoot cover. In northwestern Czech Republic, coltsfoot cover decreased on reclaimed spoil heaps as woody vegetation increased during 35 years. Coltsfoot was not present the first 5 years but was abundant at 5 to 8 years when herbaceous perennials started to dominate. Coltsfoot cover declined as cover of other perennial herbs increased, and 15 years after abandonment, cover of other perennial herbs was dense. In subsequent years, coltsfoot and other perennial herbs declined as woody species cover increased [45]:
Percent coltsfoot cover on spoil heaps in a reclaimed coal mine in northwestern Czech Republic [45] | ||
Years since reclamation | Mean percent coltsfoot cover | Mean woody species cover |
1-5 years | not present | present with negligible cover |
6-10 years | 20.5 | 1.0 |
11-15 years | 4.9 | 6.4 |
16-25 years | 2.6 | 9.0 |
26-35 years | 0.3 | 15.0 |
35-45 years | 3.1 | 10.0 |
In an abandoned fly ash waste dump in the Lee Valley, southern England, coltsfoot was abundant during early succession. Coltsfoot cover in 7-year-old and 10-year old dumps was 50% and 30%, respectively. After about 10 years, coltsfoot began to be shaded out by willow (Salix spp.) and birch (Betula spp.). Coltsfoot cover in 12- to 14-year-old ash dumps was 1% to 20%. After about 25 years, dumps succeeded to willow-birch woodlands. Coltsfoot was absent from a 24-year-old dump [85]. In central Finland, coltsfoot cover was about 2% in young peat fields (1-2 years after abandonment), but coltsfoot was absent from old peat fields (5-8 years after abandonment). Six to 8 years after abandonment, the ground was totally covered by mosses (Polytrichum spp.), and willow and birch dominated the shrub layer [81]. Coltsfoot and quackgrass (Elymus repens) dominated a 1-year-old abandoned agricultural field in Poland. Coltsfoot cover declined each succeeding year until postdisturbance year 4, when the site was dominated by orchardgrass (Dactylis glomerata) and quackgrass, and only trace coltsfoot cover was present. The authors suggested that coltsfoot rhizomes were apparently not able to grow through the thick, dense layer of rhizomes and roots of the dominant grasses [65].
Coltsfoot prefers full sun and may be favored by high-light conditions following disturbance. Coltsfoot dominated some highly disturbed gravel riverbanks in boreal forest in Gros Morne National Park, Newfoundland. The author surmised that bare soil and high light intensities created by regular disturbance along the riverbank favored coltsfoot establishment [80]. Several North American studies indicate that coltsfoot is often found in edge habitats but absent in interior forest habitats [21,56,59].
Rounded Global Status Rank: GNR - Not Yet Ranked
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | NatureServe |
Source | http://explorer.natureserve.org/servlet/NatureServe?searchName=Tussilago+farfara |
Colt's-foot is a perennial species that arises from rhizomes (3). The flowers, which are present from February to April (6), close at night and in poor weather and are pollinated by a range of flies and bees (2) (1). The seeds are dispersed by wind, but to seedlings require constantly moist conditions to survive. Most plants spread from the rhizome by vegetative reproduction (1). This plant has been put to a wide range of uses through the years (4). The leaves can be incorporated into salads, cooked and used to make tea. The felt from the leaves has been used as a stuffing agent and dried for use as tinder. Colt's-foot is still available in health-food outlets as a treatment for coughs and other chest problems. The plant must be boiled before being ingested as it contains substances that can be toxic to the liver (6).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/colts-foot/tussilago-farfara/ |
More info for the terms: cover, density, formation, rhizome
Coltsfoot reproduces vegetatively via rhizomes. Rhizomes may grow out from the basal leaf-axils and produce aerial shoots as early as 2 to 4 months after germination.
Coltsfoot is capable of rapid vegetative growth. Rhizomes may grow >3 feet (1 m) long between initiation and the formation of aerial shoots [4,69]. Two years after sowing and transplant experiments in the Netherlands, some coltsfoot plants on bare, moist, aerated soils grew into patches 8.2 to 11.5 feet (2.5-3.5 m) long [4]. In southeastern Ohio, a 4-year-old coltsfoot patch along a road was 16 to 20 feet (5-6 m) long [21].
Vegetative reproduction in coltsfoot may be decreased by shading and overcrowding. In the Netherlands, mean density of rhizomes in unshaded sites (206-228 rhizomes/m²) was substantially higher than mean density of rhizomes in shaded sites (0-38 rhizomes/m²) [4]:
Coltsfoot vegetative reproduction 2 years after planting at 4 sites [4] | |
Site characteristics | Mean number of rhizomes/m² |
Unshaded, moderately moist, and aerated to 30-40 cm deep* | 228 |
Shaded, moderately moist, and aerated to 50 cm deep** | 38 |
Unshaded, very moist, and aerated to 0-5 cm deep* | 206 |
Shaded, very moist, and aerated to 0-5 cm deep*** | 0 |
*Bare, unvegetated soil. **Young forests (3-4 m tall) without other groundlayer vegetation. Light intensity on the soil surface in July was 35-45% of full daylight. ***A stand of common reed (Phragmites communis). Light intensity on the soil surface in July was 60-70% of full daylight the first year and 5-10% the 2nd year. |
In a common garden in Poland, coltsfoot individuals growing under the least crowded conditions had the most vegetative shoots [66]. In a common garden in Wales, coltsfoot allocated proportionally more biomass to vegetative reproduction than to seed production at low densities; at high densities, many plants failed to produce a rhizome [69]. In a greenhouse experiment in England, the greatest increases in density as a result of vegetative spread occurred when coltsfoot plants were at low density. At the highest densities, many individuals produced no rhizomes [63]. Along a river in Poland, complete removal of aboveground vegetation resulted in a decrease in grass density and an increase in coltsfoot density the year after the disturbance. Coltsfoot vegetative stem density doubled compared to the year prior to the disturbance. Vegetative stem density peaked in postdisturbance year 2, when coltsfoot cover was up to 70%. During postdisturbance year 3, coltsfoot vegetative stem density declined to predisturbance levels and grass cover and "sodding" increased. When 50% of the aboveground vegetation was removed along the river, coltsfoot vegetative stem density increased but was markedly lower than when 100% of aboveground vegetation was removed [67].
Vegetative reproduction in coltsfoot may decrease in harsh environments. In a seedling transplant experiment in England, coltsfoot plants in harsh environments (low soil fertility; soil pH: 4.6; mean daily temperature in summer: 51.1 °F (10.6 °C)) allocated proportionally less biomass to seed production and more to vegetative reproduction than did those in milder environments (high soil fertility; soil pH: 7.9; mean daily temperature in summer: 58.1 °F (14.5 °C)) [13]. In a common garden in Wales, total rhizome production was greater in fertile soils than in nutrient-poor soils [69].
Information on state-level noxious weed status of plants in the United States is available at Plants Database.
Colt's foot is one of the earliest flowers each spring. The alternative name 'son-before-father' refers to the fact that the bright yellow flowers held on purplish woolly shoots are often present before the leaves (4) (5). The large leaves with their thick felt-covered undersides occur in rosettes (2). They are similar in shape to animal hooves, hence the names colt's or foal's-foot. The scientific name Tussilago derives from the latin for 'cough' (Tussis), and hints at the widespread smoking of the dried leaves in folk-medicine to cure coughs (4) (5). It is still smoked in some areas today as herbal tobacco, and the names 'baccy plant' and 'poor-man's-baccy' survive in some parts of Britain (4).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/colts-foot/tussilago-farfara/ |
More info for the terms: competition, density
Coltsfoot plants grow best in moist soils in full sun in areas with low vegetation abundance.
Although coltsfoot seeds can germinate equally well in light and in dark [4,10,64], coltsfoot seedling establishment and growth are optimum under full light, and shading delays growth. In field experiments in the Netherlands, coltsfoot seedling growth was best at 100% full light; seedling growth was delayed at 60% to 70% full light; and seedlings died at light intensities <20% full light [4]. In a greenhouse experiment in England, coltsfoot plants grown under 10% daylight had a mean dry weight of 7 mg, whereas plants grown at 70% daylight had a mean dry weight of 8,770 mg [63]. In southeastern Ohio, coltsfoot stem number tended to decrease with increased canopy closure, indicating increased coltsfoot recruitment under an open canopy [21].
Coltsfoot seedling establishment and growth appear to be optimum in moist but not saturated soils. In the Netherlands, coltsfoot seedlings were "hardly affected" by very moist and "badly aerated" soils. Conversely, many coltsfoot seedlings did not survive the first growing season in areas with low water availability in the upper soil surface in June [4].
Dense vegetation decreases coltsfoot seedling growth and establishment, probably due in part to competition with other plants for light and moisture. In field experiments in the Netherlands, coltsfoot did not grow well from germination to the reproductive stage when grown among dense agricultural crops, a result attributed in part to low light under these crops [4]. In a greenhouse in Poland, coltsfoot seedling survival decreased with increased sowing density; survival was 92% when 20 seeds were sown per tray and 19% when 500 seeds were sown per tray [66]. In field experiments in the Netherlands, coltsfoot seeds were planted at different densities in full sun in May. Sites with the lowest density showed the highest total vegetative production, and those with the highest density showed the highest mortality at the end of the first growing season. Most mortality occurred during drought at the end of June. Soil erosion and pathogens may have also caused some mortality [4]:
Survival of coltsfoot seedlings to reproductive stage from seeds planted at 4 densities in 2 experiments [4] | |
Mean number of seedlings/dm² shortly after emergence | Mean number of plants/dm² in the reproductive stage before the end of the first growing season |
28-36 | 0-1 |
11-18 | 3-4 |
8 | 4 |
2-3 | 1-2 |
Coltsfoot seedlings are apparently most vulnerable to mortality prior to development of rhizomes, when seedlings are not capable of vegetative reproduction [4]. Two and 3 years after complete removal of aboveground vegetation along a river in Poland, a large number of coltsfoot seedlings germinated in May. However, about 90% of seedlings had died by the end of the growing season [67].
Not threatened (3).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/colts-foot/tussilago-farfara/ |
Canada
Origin: Exotic
Regularity: Regularly occurring
Currently: Unknown/Undetermined
Confidence: Confident
United States
Origin: Exotic
Regularity: Regularly occurring
Currently: Unknown/Undetermined
Confidence: Confident
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | NatureServe |
Source | http://explorer.natureserve.org/servlet/NatureServe?searchName=Tussilago+farfara |
More info for the terms: fresh, natural
Coltsfoot seeds do not show dormancy. Secondary dormancy does not occur in coltsfoot. Seeds usually germinate the season they are produced [10]. Under laboratory and natural conditions, seed viability decreases rapidly over time. Most seeds >5 months old do not germinate [4,10,64]. Under laboratory conditions in the Netherlands, mean percent germination of coltsfoot seeds decreased from 94% immediately after harvest to 3% 4 months later [4]:
Mean percent germination of coltsfoot seeds immediately after harvest and after storage under varied conditions [4] | ||||
Storage conditions | Storage time | |||
Immediately after harvest | 1 month | 2 months | 4 months | |
Indoors, 18-23 °C | 94 | 57 | 41 | 3 |
Outdoors, 40 cm below the soil surface | 94 | 21 | 3 | 0 |
Outdoors, 50 cm below the water surface | 94 | 37 | 0 | 0 |
Coltsfoot seeds collected in May from wild populations in Poland and sown on filter paper in May and June reached 100% germination within 24 hours. Seeds sown in July reached 92% germination within 3 days; those sown in September reached 4.7% germination in 6 days; none of those sown in October germinated [64]. All coltsfoot seeds collected in April and May from wild populations in England and planted immediately after harvesting germinated in the laboratory. All seeds stored for 8 weeks at 37 °F (3 °C) also germinated in the laboratory, suggesting no loss of viability during 8 weeks of storage. However, all seeds stored at 37 °F for 6 months, then stored for an additional 6 months either at 81 °F (27 °C) in the laboratory or buried in mesh bags in potting soil outside, failed to germinate [10].
Viability and germination of coltsfoot seeds in the laboratory are high [4,10,64] but may not reflect germination rates in wild populations [64]. In laboratory experiments, viability reported for coltsfoot seeds from wild populations ranged from about 52% [11] to 76% [10]. However, seed germination in the field may be much lower than that in the laboratory. Namura-Ochalska [64] reported that even in years of high seed production, "no more than a few seedlings emerged", with as few as 0.5% of seeds germinating.
Coltsfoot seeds germinate in a range of light, temperature, soil moisture, and soil pH conditions, but cold temperatures and dry or extremely acid soils inhibit germination. Coltsfoot seeds germinate equally well in light and in dark [4,10,64]. Fresh coltsfoot seeds germinate at constant temperatures ranging from 41 to 86 °F (5-30 °C) [10], but >50 to 77 °F (10-25 °C) is optimum [4,6,10]. Coltsfoot seeds germinate well on substrates with a range of water availability, although they germinate best on moist substrates [10,64]. In the laboratory in Poland, seedling emergence tests indicated that coltsfoot seeds tolerated excess water, including submergence, but were very susceptible to water shortage [64]. In a culture solution, coltsfoot seeds germinated at a pH ranging from 4.5 to 6.5; germination was "slow" at pH 4; and no seeds germinated at pH <3.5 [62].
Seedling emergence tests indicate that coltsfoot seeds germinate best when on the soil surface, and seeds buried deeper than 0.2 inch (0.5 cm) [4] to 0.8 inch (2 cm) [64] do not germinate. In the laboratory in Poland, 100% of seeds planted on the soil surface germinated within 2 days; 50% germinated within 9 days when planted 0.4 inch (1 cm) deep; and 12% germinated within 12 days when planted 0.8 inch (2 cm) deep. Seeds sown deeper did not germinate [64].