Clematis vitalba (old man's beard)
- Summary of Invasiveness
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Plant Type
- Distribution Table
- History of Introduction and Spread
- Risk of Introduction
- Habitat List
- Hosts/Species Affected
- Host Plants and Other Plants Affected
- Growth Stages
- Biology and Ecology
- Latitude/Altitude Ranges
- Air Temperature
- Rainfall Regime
- Soil Tolerances
- Natural enemies
- Notes on Natural Enemies
- Means of Movement and Dispersal
- Pathway Vectors
- Plant Trade
- Impact Summary
- Environmental Impact
- Impact: Biodiversity
- Social Impact
- Risk and Impact Factors
- Uses List
- Similarities to Other Species/Conditions
- Prevention and Control
- Distribution Maps
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PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Clematis vitalba L.
Preferred Common Name
- old man's beard
International Common Names
- English: evergreen clematis; traveller's joy; virgin's bower
- French: clématite des haie; clématite vigne blanche; herbe au gueux
- Portuguese: vide branca
Local Common Names
- Belgium: bosdruif
- Denmark: almindelig skovranke; skovranke
- Finland: saksankärhö
- Germany: Echte Waldrebe; Gemeine Waldrebe; Gewöhnliche Waldrebe; Waldrebe; Weisse Waldrebe
- Italy: clematide; clematide vitalba; vezzadro
- Netherlands: bosrank
- Norway: tysk klematis
- Poland: powójnik pnacy
- Sweden: skogsklematis
- CLVVT (Clematis vitalba)
Summary of InvasivenessTop of page C. vitalba produces many seeds that are wind dispersed, and it is a strong colonizer of disturbed ground. It is a fast-growing vine with the ability to climb up and bring down tall trees and reduce standing forests to impenetrable low-growing infestations of the vine. It has the ability to expand its range and cover in Europe, North America, Australia and New Zealand, and to be further introduced as an ornamental species. It is a very serious environmental weed in New Zealand undergoing eradication.
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Spermatophyta
- Subphylum: Angiospermae
- Class: Dicotyledonae
- Order: Ranunculales
- Family: Ranunculaceae
- Genus: Clematis
- Species: Clematis vitalba
Notes on Taxonomy and NomenclatureTop of page The name 'vitalba' is derived from the Latin words for 'white vine', referring to the mass of white flowers that cover vines in summer. The common name, 'traveller's joy', also refers to this massive floral display, whereas the common names 'old man's beard' and 'virgin's bower' refer to the creamy mass of feathery achenes that hang on the bare canes through winter. Other common names are used regionally in England (West, 1991). Common names in other languages evoke the forest and hedgerow habitat that this vine inhabits. The name 'herbe au gueux' ('beggars plant') is said to originate from the use of the acrid juice of the plant to produce ulcerous wounds as a means of exciting pity (West, 1991). There are no taxonomic synonyms for this species. Several varieties have been recorded, but these are probably phenotypic variations in response to habitat.
DescriptionTop of page C. vitalba is a deciduous, woody climber that can live for 40 years (West, 1991) or more. Woody stems can grow to over 10 m in length and can reach 15-20 cm in diameter. New stems are deeply ridged, dark purple and green, with silky white hairs near the apex, and have been recorded to grow as much as 3 m per year (West, 1991). Stems grow erect between holds, rather than entwining a vertical stem. A shoot can support itself for some distance before twining 3-4 times around a new hold of approximately 1 cm in diameter (Kennedy, 1984; West, 1991). Vines can climb 25 m-tall forest trees, but have difficulty colonizing tall, emergent species with long distances between branches (Ogle et al., 2000). Mature stems have grey, stringy bark, with thickened nodes approximately 15 cm apart. Where stems grow along the ground, adventitious roots form at the nodes.
Leaves are opposite, and almost all comprise five 3-10 cm leaflets with long petioles. Leaflets are variable in size and shape, ovate, acute to acuminate, rounded or sub-cordate at the base, and coarsely toothed or entire (Cronk and Fuller, 1995). Leaves have light- and shade-forms (Kennedy, 1984). The flowers are solitary, in terminal or axillary cymes. Flowers are small (c. 2 cm), white to greenish-white, usually hermaphrodite, and without petals (Clapham et al., 1987). The achenes are compressed, 2.0-2.5 mm long. Each retains a feathery style that is 2-3 cm long. Achenes are produced in large heads.
Plant TypeTop of page Broadleaved
Vine / climber
DistributionTop of page C. vitalba is native to Europe, from southern England and the Netherlands to North Africa, and from Spain to the Middle East and the Caucasus. It is naturalized in European countries bordering its contiguous native range, including Ireland, Poland, Norway and Sweden (Tutin et al., 1964) and it also grows north of its native European range, for example in northern England and Scotland. It has been introduced to, and has naturalized in, North America, Australia and New Zealand. The best means for estimating distribution in Europe appears to be mean temperature in July (Fitter, 1978).
Distribution TableTop of page
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.
History of Introduction and SpreadTop of page C. vitalba has been introduced widely throughout the world as a garden ornamental, and has naturalized in Europe, North America, and Australasia. Gardeners in Philadephia and Boston, USA imported several Clematis species including C. vitalba between 1830 and 1840 (ACS, 2003). It was first recorded in New Zealand in the 1920s and had become naturalized by 1935 (West, 1991), but it was not until the 1960s that this plant was recognized as a threat.
Risk of IntroductionTop of page C. vitalba seeds could be imported between continents as contaminants on trade items. However, this plant is not commonly associated with agricultural or industrial goods. Such events are therefore likely to be rare, and the risk low. However, C. vitalba often grows on roadsides, and the risk of seeds being transported on road vehicles from known infestations to new sites within continents is high. In the past, ornamental Clematis species were often grafted onto C. vitalba rootstocks. It is likely that some incursions of C. vitalba have resulted from reversion of these rootstocks. The highest risk of introduction remains via intentional introduction of the plant as an ornamental, and plants and seed continue to be sold by nurseries, mail order catalogues and websites.
HabitatTop of page C. vitalba is a versatile plant capable of growing in a variety of habitats, on a variety of substrates from trees and shrubs in forest margins to hedgerows, fencelines, dunes, riverbanks, and grassland. It is commonly associated with degraded and disturbed areas (Beekman, 1980), and so can be invasive within its native range. In both its native and exotic range, C. vitalba typically occupies forest margins and gaps and can invade open spaces. The distribution of C. vitalba in England is mainly on chalk and limestone, but elsewhere in Europe it occurs on a wide range of moderately fertile, well-drained soils. In New Zealand it is often associated with riverbeds, and fertile alluvial soils (Atkinson, 1984; West, 1991). It does not appear to be unusually sensitive to soil acidity or nutrient deficiency although heavy soils may restrict growth and spread (Atkinson, 1984). Its native range is in the latitudinal range 36-52°N, and it does not thrive north of 36°S. It is a lowland species in New Zealand, suggesting that it is limited by cooler temperatures at high elevation (Atkinson, 1984). In North America it occurs near the coast or on the Great Lakes at latitudes similar to those in Europe (Anon., 2003). These distributions suggest that C. vitalba is a warm temperate species although infestations can occur in microhabitats within regions that otherwise appear inhospitable (Atkinson, 1984). C. vitalba also invades riparian vegetation, waste land, long grass, and even urban areas (Atkinson, 1984; Buxton, 1985; West, 1991). C. vitalba seedlings are readily grazed, and as such C. vitalba is often confined to ungrazed areas (West, 1992).
Habitat ListTop of page
|Terrestrial – Managed||Managed forests, plantations and orchards||Present, no further details||Harmful (pest or invasive)|
|Managed grasslands (grazing systems)||Present, no further details|
|Disturbed areas||Present, no further details||Harmful (pest or invasive)|
|Rail / roadsides||Present, no further details||Harmful (pest or invasive)|
|Urban / peri-urban areas||Present, no further details||Harmful (pest or invasive)|
|Terrestrial ‑ Natural / Semi-natural||Natural forests||Present, no further details||Harmful (pest or invasive)|
|Natural grasslands||Present, no further details|
|Riverbanks||Present, no further details||Harmful (pest or invasive)|
|Wetlands||Present, no further details|
|Coastal areas||Present, no further details|
Hosts/Species AffectedTop of page C. vitalba is a minor weed of vineyards, and damages small trees and hedgerows in its native and introduced ranges in Europe (Britt, 1994; Clay and Dixon, 2000) as well as being a weed of pine (Pinus spp.) plantations (Mitchell, 1975).
Host Plants and Other Plants AffectedTop of page
Growth StagesTop of page Vegetative growing stage
Biology and EcologyTop of page Genetics
Several studies confirm that the species is diploid, with 2n=16 chromosomes (Pastor et al., 1984; Ozyurt et al., 1997). C. vitalba has been artificially hybridized with other species to produce vigorous garden varieties such as C. 'jouiniana' (C. vitalba x C. davidiana or C. vitalba x C. heracleifolia) and C. 'Paul Farges' ('summer snow') (C. vitalba x C. potanini).
Physiology and Phenology
Bare stems produce leaves in mid-spring, and stem growth is rapid until flowering begins in mid-summer. Inflorescences continue to form as the stem elongates over summer. Achenes form from late summer, are retained on the plant, and fall in late winter or early spring. In New Zealand, there is phenological variation between sites that appears to be related more to microclimatic conditions than latitude or elevation (West, 1992). Seeds require winter-chilling to maximise germination. Hydrated seeds do not survive long, and the dense feathery seed loads hanging in plants over winter can be regarded as a dry, aerial seed bank from which seeds can fall at any time of year. Optimal germination of C. vitalba requires after-ripening of the seeds at temperatures lower than 15°C, and preferably alternating temperatures (Lhotska, 1974; West, 1992). Optimum temperatures and germination success of C. vitalba seeds varied with the duration of winter after-ripening, and this synchronised germination to the optimum period in spring. Similarly, Czekalski (1987) found that germination of seeds collected from plants in the autumn was poor (0-21%) compared to germination of seeds collected from the same plants in the following spring.
Seedlings form basal rosettes of single or trifoliate leaves, and after several months produce one or more elongating shoots bearing quinquefoliate leaves. Mature leaders grow 2.0-2.5 m per annum on average (West, 1992). C. vitalba can attain densities of over 7000 stems/ha and a fresh weight increment of 6.3 kg/m²/year. Stems at one New Zealand site grew an average 2.3 m in 1 year, producing 20 new nodes, with secondary stems developing from some of these nodes (West, 1992). Stem diameter and stem rings may not be good indicators of age (West, 1991).
Seedlings do not flower before the third year (Kennedy, 1984). Flowers are slightly protandrous. Insects visit C. vitalba flowers, but flowers do not appear to be self-incompatible (West, 1992), and pollination can be successful without the attention of insects. West (1992) recorded an average production of 780 viable seeds/m² per year at one New Zealand site, and found 160-900 seeds/m² in the soil. It was estimated that seed might last as long as 5 years in the soil, but no longer than 10 years.
C. vitalba grows on well-drained, moderately fertile soils (pH 5.5-8.0) and it is unlikely that poorly drained soils or arid areas will support this species. It responds well to the application of lime but is not restricted to calcareous sites. Plants respond to the addition of calcium and phosphorus (Hume et al., 1995) and to nitrogen (Bungard et al., 1998). The growth and spread of C. vitalba may be restricted by extremely acid soil conditions and by very low concentrations of nitrogen, phosphorus, calcium, sulphur and possibly manganese in the soil. However, it does not appear to be unusually sensitive to soil acidity or nutrient deficiencies (Groppe 1991; Hume et al., 1995). It is somewhat tolerant of saline soils.
Seedlings planted within undisturbed forest in New Zealand do not persist, and low irradiance appears to be the primary factor limiting establishment. Under controlled conditions, seedlings achieve maximum growth in full sunlight (100% Ir), substantial growth as low as 10% Ir, and little growth at 3% Ir. Seedlings raised at 1% Ir do not survive (Baars and Kelly, 1996; Bungard et al., 1998). Bungard et al. (1998) studied one forest remnant and suggested that germination and growth in response to light and nitrogen could account for the observed pattern of establishment and success of C. vitalba in New Zealand.
It is generally found in Europe only where annual rainfall is greater than 800 mm, and in New Zealand where rainfall is 800-1600 mm (Atkinson, 1984). Otherwise, little has been published on the climatic limits of C. vitalba.
Latitude/Altitude RangesTop of page
|Latitude North (°N)||Latitude South (°S)||Altitude Lower (m)||Altitude Upper (m)|
Air TemperatureTop of page
|Parameter||Lower limit||Upper limit|
|Mean maximum temperature of hottest month (ºC)||16||19|
RainfallTop of page
|Parameter||Lower limit||Upper limit||Description|
|Mean annual rainfall||800||1600||mm; lower/upper limits|
Rainfall RegimeTop of page Winter
Soil TolerancesTop of page
Natural enemiesTop of page
Notes on Natural EnemiesTop of page In 1989-90, a field survey identified 81 phytophagous species that attacked C. vitalba in central Europe, including 31 insects, four mites and four nematode species that were regarded as monophagous or oligophagous (Groppe, 1991; Wittenberg and Groppe, 1991, 1992; Wittenberg and Schroeder, 1993; Wittenberg, 1994). A field survey for plant pathogens was carried out in Europe and North America in 1990. Pathogenic fungi were isolated from 57 collections from nine countries (Spiers, 1991; Gourlay et al., 2000).
Means of Movement and DispersalTop of page Natural Dispersal (Non-Biotic)
The feathery styles assist wind dispersal of achenes (West, 1991) but propagules can also be spread along watercourses.
Vector Transmission (Biotic)
Dumping of garden waste containing C. vitalba vines onto roadsides has been a significant cause of spread in New Zealand (West, 1992). Achenes can be spread by adhesion to animals.
This weed appears to invade along roadsides by seed, possibly aided by the turbulence created by motor vehicles.
C. vitalba is an attractive climber, and was originally introduced to New Zealand, Australia and the USA as an ornamental.
Plant TradeTop of page
|Plant parts liable to carry the pest in trade/transport||Pest stages||Borne internally||Borne externally||Visibility of pest or symptoms|
|Fruits (inc. pods)||seeds|
|Stems (above ground)/Shoots/Trunks/Branches|
|True seeds (inc. grain)||seeds|
|Plant parts not known to carry the pest in trade/transport|
|Growing medium accompanying plants|
Impact SummaryTop of page
|Fisheries / aquaculture||None|
ImpactTop of page C. vitalba is generally regarded as a minor weed in European vineyards. However, Angelini et al. (2003) identified a phytoplasma in C. vitalba that is associated with a serious grape disease and it is also a host for Alfalfa mosaic virus (Polak, 1986). They highlighted the risk of disease transmission posed by wild plants such as C. vitalba growing in or near vineyards. C. vitalba is largely an environmental weed in New Zealand, and causes little direct economic damage. However, the total cost expended by the New Zealand Department of Conservation to manage the impact of C. vitalba in native habitats from 1989 to 1994 was approximately US$500,000 (Gourlay et al., 2000; Hill et al., 2001), and total expenditure by all agencies over this period exceeded US$2 million (Hill et al., 2001). C. vitalba is also poisonous to grazing animals but the direct costs of this to the livestock industry has not been quantified (West, 1991).
Environmental ImpactTop of page C. vitalba is not a significant environmental weed in Europe, North America, or Australia. Only in New Zealand has it caused serious environmental damage. C. vitalba infestation can reduce the forest structure, and change the recruitment patterns in forests (Ogle et al., 2000). It grows so strongly in forest margins and light gaps that vines can form a dense, light-absorbing canopy that suppresses all vegetation beneath it and can be so vigorous that the weight of foliage and stems breaks the supporting trees. C. vitalba can reduce small, healthy forest remnants to low, long-lived thickets of vines scrambling over the ground on forest debris (Hill et al., 2001).
Impact: BiodiversityTop of page Apart from changing forest structure, C. vitalba contributes to loss of biodiversity in New Zealand through local extinction of species or forms that are threatened, have restricted or disjunct distributions, or are biogeographically significant. It is common in National Parks and Reserves and infestations are a serious threat to the survival of many native forest remnants (Timmins, 1984; Ogle et al., 2000). Damage from C. vitalba also enhances invasion of native habitats by other invasive plants. Ogle et al. (2000) also point out that measures taken to control C. vitalba can also be damaging to biodiversity. C. vitalba does not hybridize with native Clematis species.
Social ImpactTop of page Contact with C. vitalba foliage can cause irritant dermatitis in humans. Moore (1971) found the stems and leaves of C. vitalba in the rumen of an 18-month-old cow that died with symptoms consistent with poisoning. However, the toxicity of C. vitalba appears to vary seasonally and it can be controlled by judicious grazing (West, 1991). C. vitalba grows as a dense vertical curtain in forest margins or along the ground as a deep mass of wiry stems restricting access to affected areas by animals and humans. C. vitalba is clearly perceived as a serious social threat by the New Zealand public. Greer and Sheppard (1990) used a contingent valuation method to assess the value that New Zealanders placed on obtaining a solution to this problem. The public was prepared to pay US$22-56 million for research that provided a 'relatively small' likelihood of controlling the weed biologically.
Risk and Impact FactorsTop of page Invasiveness
- Invasive in its native range
- Proved invasive outside its native range
- Highly adaptable to different environments
- Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
- Highly mobile locally
- Has high reproductive potential
- Has propagules that can remain viable for more than one year
- Negatively impacts agriculture
- Negatively impacts human health
- Negatively impacts animal health
- Negatively impacts tourism
- Reduced amenity values
- Reduced native biodiversity
- Competition - monopolizing resources
- Pest and disease transmission
- Highly likely to be transported internationally deliberately
- Difficult to identify/detect as a commodity contaminant
- Difficult/costly to control
UsesTop of page C. vitalba shoots are harvested and eaten in Italy (Pieroni, 1999) and other parts of Europe. Shoots must be boiled to inactivate the toxin protoanemonine (Pieroni, 1999). C. vitalba is also used as a ritual botanical to ward off evil spirits and 'turn away the evil eye' in Tuscany (Pieroni and Giusti, 2002). Leaf decoctions are used in homeopathic medicines for the treatment of urinary tract problems, and to treat inattention and shock. Flower essences are used in treatment of day-dreaming and inattention. There appear to be no recent references to the use of C. vitalba as a rootstock, but this appears to have been common practice in the past. The vigorous and sprawling habit of C. vitalba has been used to stabilize loose, stony slopes (Fisun, 1966). C. vitalba wood has wide vessels and Colville et al. (1979) suggested that carbonized wood of C. vitalba could be used as a matrix for bone regeneration in the treatment of fractures. It is principally used as an ornamental species.
Uses ListTop of page
- Graft stock
- Poisonous to mammals
Similarities to Other Species/ConditionsTop of page Keys successfully distinguish C. vitalba from sympatric Clematis species in Europe by flower colour and structure, and by climbing habit. C. vitalba achenes are barely compressed whereas achenes of C. flammula are strongly compressed (Tutin et al., 1964). C. vitalba can be distinguished from C. tangutica because it has white rather than deeply yellow flowers, and because leaves are coarsely rather than finely toothed (Atkinson, 1984).
Prevention and ControlTop of page Cultural Control
Sheep grazing will control C. vitalba seedlings and young vines growing at ground level, but potential damage to rare and endangered plants may make this approach questionable in many infested sites (Ogle et al., 2000).
Small seedlings can be removed by hand. Vines can be cut and pulled from trees by hand once the foliage has dried. Roots can be dug out, but should be placed off the ground where they cannot take root again. Treating cut stems with herbicides will also kill crowns and roots (Britt, 1994). Vines growing along the ground can be uprooted, but can regenerate from stem fragments left behind. Foliage trimming has no apparent effect on plants (Britt, 1994).
C. vitalba foliage growing on fencelines, in wasteland, or as a monoculture can be successfully sprayed. A range of herbicides can be used to spray C. vitalba, including glyphosate, imazapyr, metsulfuron (Clay and Dixon, 2000) and clopyralid (Downard, 1986). Herbicide should be applied to pre-flowering foliage from late spring to late summer. Where broadcast spraying could have non-target effects, find the crown, cut the vines to ground level or to waist level in the winter or spring and spray the foliage that regenerates from crowns and stems in late summer. Alternatively, applying full strength herbicide by paint brush or dropper to the cut surface immediately after stems are cut close to the ground will also kill crowns and roots. Ward et al. (2000) found that a gel formulation of picloram was an effective stump treatment. These approaches impact least on surrounding vegetation. Growing in inaccessible areas can make adequate chemical control either too expensive to apply, or unsafe because the weed is interwoven with valued indigenous plants. Nevertheless, aerial spraying of native forest reserves has been conducted on the assumption that possible death of non-target plants from herbicide application is preferable to certain death in the darkness under the canopy of C. vitalba.
Three biological control control agents for C. vitalba have been released in New Zealand. Phytomyza vitalbae (Agromyzidae) was released in 1996, and spread widely (Hill et al., 2001). Laboratory studies suggest that moderate mining of leaves can significantly reduce the growth rate of seedlings, but the impact of this insect on C. vitalba in New Zealand has yet to be fully evaluated. Phoma clematidina (anamorphic Pleosporaceae) was also released in 1996, and is now widespread. This fungus causes leaf and stem necrosis, wilting, premature defoliation, and sometimes girdles stems (Gourlay et al., 2000). Epidemics have been observed, but their impact on C. vitalba infestations has not been measured. The sawfly Monophadnus spinolae (Tenthredinidae) has been released widely in New Zealand, but there is no evidence of establishment (Gourlay et al., 2000).
C. vitalba grows rampantly on alluvial soils and over riparian vegetation. It is important to treat upstream infestations first to restrict re-invasion by water- and wind-blown seed.
ReferencesTop of page
ACS (American Clematis Society), 2003. The ACS timeline of clematis history. American Clematis Society. www.clematis.org.
Angelini E; Squizzato F; Luccheta G; Borgo M, 2003. Identificazione di un fitoplasm associate a flavescenza dorata su Clematide (Clematis vitalba). http://www.ispave.it/CONVEGNO/Fitosessione4.htm.
Anon., 2003. Clematis alba, old man's beard. The Canadian Biodiversity Web Site. Canadian Heritage. www.canadianbiodiversity.mcgill.ca/english/species/plants/plantpages/cle_vit.html.
Atkinson IAE, 1984. Distribution and potential range of old man's beard, Clematis vitalba, in New Zealand. Information Series, Department of Lands and Survey, Wellington, New Zealand, 11:6-25.
Beekman F, 1980. The dynamics of an alluvial forest on the Rhine and the role of climbers. In: Cramer J, ed. Colloques phytosociologiques: forets alluviales europeennes, Strasbourg.
Britt CP, 1994. Clematis vitalba (old man's beard) as a competitive "weed" in hedgerows and the effects of hedge cutting regimes on its development. Field margins: integrating agriculture and conservation. Proceedings of a symposium held at Coventry, UK, 18-20 April 1994 [edited by Boatman, N.] Farnham, UK; British Crop Protection Council (BCPC), 241-246
Bungard RA; Morton JD; McNeil DL; Daly GT, 1998. Effects of irradiance and nitrogen on Clematis vitalba establishment in a New Zealand lowland podocarp forest remnant. New Zealand Journal of Botany, 36(4):661-670; 26 ref.
Buxton JM, 1985. The potential for the biological control of Clematis vitalba L. MSc Thesis, Imperial College, Silwood Park, Egham: Department of Pure and Applied Science.
Clapham AR; Tutin TG; Moore DM, 1987. Flora of the British Isles. Third edition. Cambridge, UK: Cambridge University Press.
Colville J; Baas P; Hooikka V; Vainio K, 1979. Wood anatomy and the use of carbonised wood as a matrix for bone regeneration in animals. IAWA Bulletin, 1:3-6.
Czekalski M, 1987. Germination capacity and seedling morphology in Clematis vitalba L. Prace Komisji Nauk Rolniczzych I Komisji Nauk Lesnych, 63:15-20.
Downard P, 1986. Herbicides for control of old man's beard. Proceedings of the thirty-ninth New Zealand Weed and Pest Control Conference. Palmerston North, New Zealand; New Zealand Weed and Pest Control Society, 108-109
Fisun MN, 1966. Some woody climbers of the Black Sea coast of the Caucasus, and their use for fixing loose slopes. Lesn. Z., Arhangel'sk, 9:44-46.
Fitter A, 1978. An atlas of the wild flowers of Britain and Northern Europe. London, UK: Collins.
Gourlay AH; Wittenberg R; Hill R; Spiers AG; Fowler SV, 2000. The biological control programme against Clematis vitalba in New Zealand. In: Spencer NR, ed. Proceedings of the X International Symposium on Biological Control of Weeds, Bozeman, Montana, USA: Montana State University, 709-718.
Greer GG; Sheppard RL, 1990. An economic evaluation of the benefits of of research into biological control of Clematis vitalba. Unpublished research report. Canterbury, New Zealand: Lincoln University, 203:1-45.
Groppe K, 1991. Literature review and preliminary survey of the biotic agents associated with old man's beard, Clematis vitalba, in Europe. Unpublished report. Delémont, Switzerland: CABI Bioscience.
Hemp A, 1999. The vegetation of open limestone screes in the northern Frankenalb. Tuxenia, 19:241-304.
Hill RL; Wittenberg R; Gourlay AH, 2001. Biology and host range of Phytomyza vitalbae and its establishment for the biological control of Clematis vitalba in New Zealand. Biocontrol Science and Technology, 11(4):459-473; 26 ref.
Hume L; West CJ; Watts HM, 1995. Nutritional requirements of Clematis vitalba L. (old man's beard). New Zealand Journal of Botany, 33:301-313.
Kennedy PC, 1984. The general morphology and Ecology of Clematis vitalba. Information Series, Department of Lands and Survey, Wellington New Zealand, 11:26-36.
Lhotska M, 1974. The after-ripening of embryos on the mother plant. Folia Geobotanica et Phytotaxonomica, 9:231-240.
Maire R, 1964. Flore de L'Afrique du Nord, Vol. 11. Paris, France: Paul LeChevalier.
Mitchell AF, 1975. Three forest climbers, Ivy, old man's beard, and honeysuckle. Forestry Commission Forestry Record, HM Stationery Office, 1-12.
Moore RHS, 1971. Poisoning by old man's beard (Clematis vitalba)? Veterinary Record, 89:569-570.
Ogle CC; Cock GDla; Arnold G; Mickleson N, 2000. Impact of an exotic vine Clematis vitalba (F. Ranunculaceae) and of control measures on plant biodiversity in indigenous forest, Taihape, New Zealand. Austral Ecology, 25(5):539-551; 27 ref.
Ozyurt SL Senal G; Ozkan M, 1997. Karyotype analysis of three Clematis L. (Ranunculaceae) species. Turkish Journal of Botany, 21:285-289.
Pastor DJ; Fernandez I; Diez MJ, 1984. Chromosome numbers of Spanish flora. Lagascalia, 12:281-284.
Petkova OP, 1984. Origin of pollen collected by honeybees during different seasons in Smoljan and Beden regions, Bulgaria. Godishnik na Sofiiskiya Universitet "Kliment Okhridski", Biologicheski Fakultet, 74:105-112.
Pieroni A, 1999. Gathered wild foods in the Upper Valley of the Serchio River (Garfagnana), Central Italy. Economic Botany, 53:327-341.
Pieroni A; Giusti ME, 2002. Ritual botanicals against the evil-eye in Tuscany, Italy. Economic Botany, 56:201-203.
Polak Z, 1996. Spontaneous hosts of alfalfa mosaic virus ascertained in ruderal plant associations in central Bohemia. Ochrana Rostlin, 32:161-165.
Rechinger KH, 1992. Flora de Iranischen Hochlandes und der Umrahmenden Gebirge - Ranunculaceae, Lfg 171. Graz, Austria: Akademishe Druck u. Verlagsanstalt.
Royal Botanic Gardens Sydney, 2003. Australia's Virtual Herbarium. Sydney, Australia: Royal Botanic Gardens. http://plantnet.rbgsyd.gov.au/cgi-bin/avh/avh.cgi.
Seijo MC; Jato V; Iglesias MI; Aira MU, 1997. Palynological characteristics of sweet chestnut honeys from Galicia (NW Spain). Acta Botanica Malacitana, 22:73-81.
Spiers AG, 1991. Field survey of Clematis populations in the USA, England, and Europe for potential biological control agents to control Clematis vitalba (old man's beard) in New Zealand. Unpublished Research Report: DSIR.
Timmins S, 1984. Weeds in National Parks and Reserves. Unpublished report. Wellington, New Zealand: Department of Conservation.
Tremolieres M; Schnitzler A; Sanchez-Perez JM; Schmitt D, 1999. Changes in foliar nutrient content and resorption in Fraxinus excelsior L., Ulmus minor Mill. and Clematis vitalba L. after prevention of floods. Annals of Forest Science, 56:641-650.
Tutin TG; Heywood VH; Burges NA; Valentine DH; Walters SM; Webb DA, 1964. Flora Europaea, Vol. 1. Cambridge, UK: Cambridge University Press.
USDA-ARS, 2003. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.aspx
USDA-NRCS, 2002. The PLANTS Database, Version 3.5. National Plant Data Center, Baton Rouge, USA. http://plants.usda.gov.
Ward BG; Henzell RF; Zydenbos SM, 2000. Herbicide gels for controlling old man's beard (Clematis vitalba) in ecologically sensitive areas. New Zealand Plant Protection, 53:284-288.
West CJ, 1991. Literature review of the biology of Clematis vitalba (old man's beard). DSIR Land Resources Vegetation Report No. 725. Library@landcareresearch.co.nz.
West CJ, 1992. Ecological Studies of Clematis vitalba (old man's beard) in New Zealand. DSIR Land Resources Vegetation Report No. 736. Library@landcareresearch.co.nz.
Wittenberg R, 1994. Search for potential biological control agents for old man's beard, Clematis vitalba. Unpublished annual report. Delémont, Switzerland: CABI Bioscience.
Wittenberg R; Groppe K, 1991. Search for potential biological control agents for old man's beard, Clematis vitalba. Unpublished annual report. Delémont, Switzerland: CABI Bioscience.
Wittenberg R; Groppe K, 1992. Investigations on potential biocontrol agents of old man's beard, Clematis vitalba. Unpublished annual report. Delémont, Switzerland: CABI Bioscience.
Wittenberg R; Schroeder D, 1993. Investigations on potential biocontrol agents of old man's beard, Clematis vitalba. Unpublished annual report. Delémont, Switzerland: CABI Bioscience.
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