Tree of heaven	Status LU: established. 1st record: LU <1875, ITW <2013.
	Himmelsbam	Status Eur.: established. 1st record: HU 1740s.  IAS of EU concern (2019).
	Ailante glanduleux	RA: ISEIA: C1. Harmonia+: 0,42.
	Götterbaum	Wikipedia: Wikispecies: | CABI
	Hemelboom	Back to the list of neophytes

Brief description

Ailanthus altissima (Mill.) Swingle is a fast-growing, light-demanding and thermophilic pioneer tree species. It grows best on nutrient-rich soils and is very tolerant to dryness and air pollution. It is mostly found in waste and disturbed areas, but can also invade different kinds of forest ecosystems, riparian areas, rock outcrops and semi-natural grasslands. Winged seeds are easily dispersed by wind and water over distances exceeding several hundreds of metres (Branquart et al. 2017).

Ailanthus altissima successfully displace native vegetation due to its rapid growth and root suckering. It produces allergenic toxins in bark and leaves. As these accumulate in the soil, they inhibit the growth of other plants (allelopathic interactions), favour the formation of monospecific stands and inhibit vegetation succession. Ailanthus also increases soil N content and pH. Ailanthus can reduce soil water availability in case of severe infestation. It may damage roads and other infrastructures due to strong and rapid root development (Branquart et al. 2017). The root system is aggressive enough to cause damage to sewers and foundations (GISD 2019).

Photo gallery

Alley of Alianthus altissima, Porte de France, Belval, Esch-sur-Alzette. Photos by Yan Steil, 23rd July 2014.

IAS of Union concern

In 2019, Ailanthus altissima was added to the list of invasive alien species of Union concern (Anonymous 2019) which implies that member states shall take all necessary steps to prevent it’s unintentional introduction or spread.

Status and distribution in Luxembourg

The oldest reference to Ailanthus altissima in Luxembourg is found in the flora of Krombach (1875: 108) who lists it as a cultivated species. To mention an old example, Jean Feltgen (1833-1904) included a specimen from a garden in Diekirch in his herbarium, unfortunately without mentioning a date (Specimen № 15467, MNHNL 2000-). It can still be considered the first documented record of the species before 1905, within Jean Feltgen’s lifetime.

The first documentation of the tree of Heaven in the wild dates from 2013, when Jerry Grün reports a grown specimen in a forest edge near Elvange (Ries & Krippel 2021). An earlier report on 13 July 1993 by Léopold Reichling in the Pfaffenthal district in Luxembourg City could not be verified as in the wild as it might have been part of the plantations in the gardens of the Hospice du Pfaffenthal (Obs. key: LUXNATFUND431045, MNHNL 2000-).

According to Lambinon & Verloove (2012: 463) the species is quite rare in urban areas (AR) and very rare in rural areas in the territory of the flora.

Ailanthus altissima is found in several parks in the country, including Tony Neuman Park (Hollman & Schroeder 1997: 22) and municipal park in Luxembourg City.

For two decades the species did not appear to have spread to the wild. It is only in recent years that the species was planted in several urban areas and appeared in the wild on sandstone cliffs in Luxembourg City (cf. also Krippel et al. 2020: 32).

In the median strip of Highway A1 near the port of Mertert. Photo: © Yves Krippel, 20200907,

In 2020, the salt-tolerant Ailanthus altissima was detected for the first time in a motorway median strip (A1 motorway near the port of Mertert, Yves Krippel, 2020-09-07, iNaturalist).

Considering the recent expansion of the species in Luxembourg and its probable future increased spread due to climate change, and to avoid major problems urban areas experience with the tree of Heaven as a weed across Europe, Ailanthus should not be planted any more as an ornamental tree and existing populations should be eradicated.

An identification sheet of the species has been published by the MECDD in French and German.

Ailanthus as ornamental tree in urban areas

Alley of Alianthus altissima, Porte de France, Belval, Esch-sur-Alzette. Photo: Yan Steil, 23.07.2014.

• On 23rd July 2014 a complete alley of Ailanthus altissima was discovered in the street Porte de France in Belval / Esch-sur-Alzette. It was recently planted in the course of the regeneration of the brownfield site into a large scientific and cultural centre, including the science faculty of the University of Luxembourg (Steil 2014, pers. comm.). Based on sattelite photos the alley counts more than 70 individuals.
• A group of Ailanthus altissima trees was recently planted behind the Olympic swimming pool in the Kirchberg disctrict of Luxembourg City by the Fonds du Kirchberg. Seedlings have already started to spread on this site (Helminger 2018, pers. comm.).
• A row of 9 Ailanthus altissima was planted before 2008 along a parking area behind the church of Walferdange (Welter et al. 2008: 81; map).
• A single tree is present in the section of the municipal park situated between Avenue de la Porte-Neuve and Avenue Émile-Reuter in Luxembourg City (on the side of the Avenue de la Porte-Neuve in line with two trees of Corylus colurna. Two single trees can be found in the Rue du Rollingergrund, one in front of the house n°294 and another next to the residence on n°306 (Welter et al. 2008: 81).
• A single old tree with several saplings and a single younger grown-up tree were observed on 10th June 2018 in the municipal park of Diekirch situated along the river Sûre.
• A group of 4 Ailanthus altissima trees grow in a roundabout on the N6 road north of Mersch and several seedlings / young plants have been found in the commercial zone east of the roundabout (Yves Krippel, pers. comm. 2020-10-27).

In a few decades, with climate change helping, Ailanthus might grow in many pavement rinds, flowerbeds and vague grounds all over these sites and possibly into the wild in adjacent areas, as illustrated in the following example from planted tree in a roundabout north of Mersch:

Ailanthus in the wild

In 2018, three populations of Ailanthus altissima were sighted in the wild in Luxembourg City:

• on the edge of the cliff along the railway to Wasserbillig between the Plateau du Rham and the INS. As part of a site visit on 28/11/2019 with representatives of the Nature and Forestry Administration, Public Buildings and the MNHNL, it was decided that the management of this site will take place during winter 2019-2020 and that management should be continued until the site no longer represents a danger to the railway line below.
• on the edge of the Plateau du Rham southeast of the former military canteen;
• on the sandstone cliffs above n°11 Bisserweg (Grund district, Luxembourg City).

Management

A recent study in Berlin concludes that urban management strategies concerning Ailanthus would gain support from citizens when combining multiple approaches (Kowarik et al. 2021): (i) to control the species in case of realized negative impacts; (ii) to prevent the invasion of the species in areas of conservation concern; and (iii) to develop novel approaches of integrating wild Ailanthus trees into urban green spaces. These insights could support management measures that need to be established due to the EU-Regulation on Invasive Alien Species.

Action plan

The action plan dedicated to the tree of heaven, designed to limit the spread and minimise its in Luxembourg, was drafted in 2020 (Pfeiffenschneider & Hoppe 2020) and submitted for a 60 days lasting public consultation on 9 September 2020. It clearly postulates that, if its population continues to increase, this species is likely to cause ecological and economic damage.

• Finalised Action Plan for Ailanthus altissima (Pfeiffenschneider & Hoppe 2020)
• Page of public consultation (FR)

Risk assessment

ISEIA protocol

C1 (1+1+1+1) (Ries et al. 2013: 18).

Harmonia+ protocol

0,74Invasion
0,57Impact
0,42Risk

Worldwide distribution

CABI 2014: https://www.cabi.org/isc/datasheet/3889#toDistributionMaps

Bibliography

• Anonymous, 2019. Commission implementing regulation (EU) 2019/1262 of 25 July 2019 amending Implementing Regulation (EU) 2016/1141 to update the list of invasive alien species of Union concern. Official Journal of the European Union L 199/1-2 (26.7.2019).
• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum & F. Verloove, 2017. Harmonia database: Ailanthus altissima (Mill.) Swingle. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-23]
• CABI, 2014. Ailanthus altissima (Mill.) Swingle [original text by Soraya Constán Nava]. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2019-11-26]
• GISD, 2019. Species profile: Ailanthus altissima in the Global Invasive Species Database. URL: http://www.iucngisd.org/gisd/speciesname/Ailanthus+altissima [accessed 2019-11-28]
• Hollman, A. & M. Schroeder, 1997. Parc Tony Neuman (Joyaux botanique au centre de la ville de Luxembourg, réalisé à partir de 1948 par Me Tony Neuman, notaire, Henri Luja, architecte-urbaniste, et Alphonse Hollman, jardinier en chef). AAT-Info 53, supplément. Éd. AAT – Garten und Teichfreunde Luxemburgs. Imprimerie Saint-Paul, Luxembourg. 64 pp.
• Kowarik I., T.M. Straka, M. Lehmann, R. Studnitzky & L.K. Fischer, 2021. Between approval and disapproval: Citizens’ views on the invasive tree Ailanthus altissima and its management. NeoBiota 66: 1–30. https://doi.org/10.3897/neobiota.66.63460
• Krippel, Y., T. Helminger & G. Colling, 2020. Notes floristiques. Observations faites au Luxembourg (2018-2019). Bulletin Soc. Nat. luxemb. 122 : 29-55. [PDF 132 KB]
• Krombach, J.-H.-G., 1875. Flore du grand-duché de Luxembourg. Plantes phanérogames. 564 p. Luxembourg, Imprimerie Joris.
• Lambinon J. & F. Verloove, 2012. Nouvelle flore de la Belgique, du grand-duché de Luxembourg, du Nord de la France et des régions voisines. Sixième édition. Avec la collaboration de L. Delvosalle, B. Toussaint, D. Geerinck, I. Hoste, F. Van Rossum, B. Cornier, R. Schumacker, A. Vanderpoorten et H. Vannerom. Jardin botanique national de Belgique, Meise. CXXXIX + 1195 pp. ISBN : 9789072619884.
• MNHNL, 2000-. Ailanthus altissima in Recorder-Lux, database on the natural heritage of the Grand Duchy of Luxembourg. Musée national d’histoire naturelle, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2018-01-08]
• Pfeiffenschneider, M. & Hoppe, F., 2020. Plan d’action pour espèces exotiques envahissantes au grand-duché de Luxembourg : Faux-vernis du Japon, Ailanthus altissima (Mill.) Swingle. Version 3.0 – 2020/09/20. Administration de la nature et des forêts, Luxembourg. 19 pp.
• Ries C. & Y. Krippel 2020. Ailanthus altissima (Mill.) Swingle – Distribution actuelle, recensement futur et mise en oeuvre des mesures d’éradication au grand-duché de Luxembourg. Rapport au Groupe de coordination sur les espèces exotiques envahissantes au Luxembourg (MECDD), Version 1.1 (2020-11-24). 9p.
• Ries, C. & Y. Krippel, 2021. First records of 56 invasive alien vascular plants in Luxembourg. Bulletin de la Société des naturalistes luxembourgeois 123: 115-127. [PDF 241 KB]
• Ries, C., Y. Krippel & M. Pfeiffenschneider, 2020. Risk assessment after the Harmonia+ protocol of invasive alien vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 122: 197-205. [PDF 132 KB]
• Ries, C., Y. Krippel, M. Pfeiffenschneider & S. Schneider, 2013. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of non-native vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 114: 15-21. [PDF 652 KB]
• Welter A., J.Turk & J. Trossen, 2008. Les arbres introduits au Luxembourg. Inventaire des essences arborescentes non indigènes de pleine terre présentes sur le territoire du Grand-Duché de Luxembourg. Ferrantia 53, Musée national d’histoire naturelle, Luxembourg, ISSN 1682-5519, 111 pp.

 Page content last updated on 2023-08-17. Last proofread by Caroline Grounds on 2019-11-12.

	American willowherb	Status LU: established. 1st record: LU & ITW 1950
	Drüse-Weideréischen	Status Eur.: established. 1st record: UK 1891.
	Épilobe à tige glanduleuse	RA: ISEIA: B3 – Watch List. Harmonia+: 0,15
	Drüsiges Weidenröschen	Wikipedia: | Wikispecies: | CABI
	Beklierde basterdwederik	Back to the list of neophytes

Brief description

Epilobium ciliatum Raf. is a pioneer plant species that thrives mainly in man-made environments such as arable land, gardens, tree nurseries, clearcuts and ruderal areas. It may also become established in open riparian habitats. Its seeds are adapted for wind dispersion and have a high germination rate. It is one of the arable weed species with the highest rate of increase in Europe (Branquart et al. 2010).

Status and distribution in Luxembourg

Epilobium ciliatum Raf. was first documented under its synonym Epilobium adenocaulon Hausskn. on 1950-07-19 in wasteland on sand between two spruce stands near Croix-des-Bourgeois (Biergerkräiz) near Bridel (municipality of Kopstal) by François Léon Lefort (1917-1975) and Léopold Reichling (1921-2009) (Reichling 1961: 68ff.; MNHNL 2000-; herbarium specimen N°17920).

The species, described by Haussknecht in 1879 based on American herbarium samples, is native to North America where it is widely distributed as several varieties that are difficult to define. Introduction in Europe: < 1900 (Great Britain, Russia), 1900 (Sweden), 1915 (Netherlands), 1916 (Finland), 1931 (East Prussia), 1950 (Luxembourg), 1952 (Belgium, France) (Reichling 1961: 74).

This North American plant species was naturalised in Europe around 1900; it is rapidly expanding (Lambinon & Verloove 2012: 434).

700 records of the species are listed in the MNHNL-mdata online portal and the plant is widespread throughout the country (MNHNL, iNaturalist & GBIF 2019).

Risk assessment

ISEIA protocol

B3 (3+3+2+1) = Watch List (Ries et al. 2013: 18).

Harmonia+ protocol

0,69Invasion
0,22Impact
0,15Risk

Worldwide distribution

Source: https://www.cabi.org/isc/datasheet/114114#toDistributionMaps

Bibliography

• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum, F. Verloove, 2010. Harmonia database: Epilobium ciliatum Raf.. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-09]
• CABI, 2019. . In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-02-28]
• Lambinon J. & F. Verloove, 2012. Nouvelle flore de la Belgique, du grand-duché de Luxembourg, du Nord de la France et des régions voisines. Sixième édition. Avec la collaboration de L. Delvosalle, B. Toussaint, D. Geerinck, I. Hoste, F. Van Rossum, B. Cornier, R. Schumacker, A. Vanderpoorten et H. Vannerom. Jardin botanique national de Belgique, Meise. CXXXIX + 1195 pp. ISBN : 9789072619884.
• MNHNL, 2000-. Epilobium ciliatum Raf. in Recorder-Lux, database on the natural heritage of the Grand Duchy of Luxembourg. Musée national d’histoire naturelle, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-10-09]
• MNHNL, iNaturalist & GBIF, 2019. Epilobium ciliatum Raf. in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-10-09]
• Reichling, L., 1961. Notes floristiques 1957-1958. Bull. Soc. Nat. luxemb. 63: 19-99. [PDF 4612 KB]
• Ries, C. & Y. Krippel, 2021. First records of 56 invasive alien vascular plants in Luxembourg. Bulletin de la Société des naturalistes luxembourgeois 123: 115-127. [PDF 241 KB]
• Ries, C., Y. Krippel & M. Pfeiffenschneider, 2020. Risk assessment after the Harmonia+ protocol of invasive alien vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 122: 197-205. [PDF 132 KB]
• Ries, C., Y. Krippel, M. Pfeiffenschneider & S. Schneider, 2013. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of non-native vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 114: 15-21. [PDF 652 KB]

 Page content last updated on 2021-03-03. Last proofread by Caroline Grounds on 2019-11-17.

	Bohemian Knotweed	Status LU: established. 1st record: LU & ITW 2005.
	Béimescht Knuetkraut	Status Eur.: established. 1st record ITW UK 1954.
	Renouée de bohême	RA: ISEIA: B1 – Watch List. Harmonia+: 0,59
	Bastard-Knöterich	Wikipedia: | Wikispecies: n/a | CABI
	Boheemse duizendknoop	Back to the list of neophytes

Brief description

Like other Asiatic knotweeds, Fallopia ×bohemica (Chrtek & Chrtková) J. P. Bailey colonises a wide range of environments, with a predilection for moist and nitrogen-rich soils. It prefers sunny places or semi-shaded habitats. This pioneer plant proliferates both in ruderal and semi-natural habitats, including riparian areas and open forests. Stem and rhizomes may easily split into small pieces; fragments are able to regenerate a plant, provided a node is present. The Bohemian knotweed may produce seeds but seedling establishment is usually inefficient due to frost sensitivity. Transport of garden waste and soil contaminated with rhizomes are the major dispersal modes. Where the plant is widely consolidated on river banks it is also spread by floods and can easily colonise downstream.

Fallopia xbohemica exhibits hybrid vigour and is reputed to be more invasive than the two parents, F. japonica and F. sachalinensis. It typically forms very dense stands, excluding native vegetation and prohibiting regeneration. It reduces plant and invertebrate species diversity, alters the habitat for wildlife, and changes light and energy conditions of the ecosystem. Once stands become established, they are extremely persistent and difficult to remove. Its development can favour river bank erosion during the winter (Branquart et al. 2010).

Uncertain status of Fallopia × bohemica in Luxembourg

Identification of knotweed species is not always easy, especially the very similar Japanese knotweed (Fallopia japonica) and Bohemian knotweed (Fallopia ×bohemica), a hybrid between Japanese knotweed and Sakhalin knotweed (Fallopia sachalinensis). Until recently, Japanese knotweed was considered much more widespread in Luxembourg than Bohemian knotweed.

During the field trip of the international Neobiota 2016 conference in September 2016, knotweed populations near Michelau that were so far considered as F. japonica, were identified by specialists as F. ×bohemica.

To assess the accuracy of the data collected to date, the Department of Ecology of the Museum carried out a small survey in 2017:  31 specimens of knotweed populations were collected across the country, described and filed in the museum’s herbarium. Genetic analysis of the samples in the museum’s lab showed that in Luxembourg F. ×bohemica is more common than Fallopia japonica. The data of both taxa need to be updated in the Recorder-Lux database (MNHNL, 2000-).

Status and distribution in Luxembourg

Currently, 16 records of the hybrid are accessible through the MNHNL-mdata portal (MNHNL, iNaturalist & GBIF 2019). As far as we currently know, the species is distributed along the rivers Mamer, Black Ernz and Gander.

As in the case of Fallopia sachalinensis, the frequency of male-sterile and male-fertile colonies in the environment should be specified. This hybrid, long unknown, is very variable. It could have been formed by spontaneous hybridisation of both parents; but the introduction by horticulturists of hybrid strains is equally, if not more likely (Lambinon & Verloove 2012: 193).

As outlined in the section above, the status of the species has to be revised, as many records could have been misidentified, which is why we describe both Bohemian and Japanese knotweed together in the following section.

Importance and distribution of Bohemian and Japanese knotweed in Luxembourg

Bohemian and Japanese knotweed are common and widespread invasive neophytes in Luxembourg. They build huge colonies along riparian ecosystems, several major rivers of Luxembourg being affected. They regularly grow in small patches along roadsides and in waste grounds, most of these places having been “contaminated” by people getting rid of knotweed clippings from their gardens. Examples can be seen along the main road leaving Luxembourg City in the direction of Echternach. Nurseries and garden designers sometimes contribute to the spread of knotweed in gardens and public green spaces by using contaminated compost.

Risk assessment

ISEIA protocol

B1 (2+2+3+3) = Watch List (Ries et al. 2013: 18). Needs to be reassessed (see above).

Harmonia+ protocol

0,84Invasion
0,70Impact
0,59Risk

Worldwide distribution

Source: https://www.cabi.org/isc/datasheet/108332#toDistributionMaps

Bibliography

• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum, F. Verloove & A. Vervoort, 2010. Harmonia database: Fallopia ×bohemica (Chrtek & Chrtková) J. P. Bailey. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-09]
• Bailey, J.P. & A.P. Conolly, 2000. Prize-winners to pariahs – A history of Japanese Knotweed s.l. (Polygonaceae) in the British Isles. Watsonia. 23: 93–110.[PDF]
• CABI, 2019. Fallopia x bohemica. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-03-02]
• Glesener, B., M. Pfeiffenschneider & C. Ries, 2009. Die Verbreitung von Impatiens glandulifera, Fallopia japonica, F. sachalinensis, F. ×bohemica und Heracleum mantegazzianum entlang der Hauptfließgewässer Luxemburgs. Bull. Soc. Nat. luxemb. 110: 69-73. [PDF 470 KB]
• Lambinon J. & F. Verloove, 2012. Nouvelle flore de la Belgique, du grand-duché de Luxembourg, du Nord de la France et des régions voisines. Sixième édition. Avec la collaboration de L. Delvosalle, B. Toussaint, D. Geerinck, I. Hoste, F. Van Rossum, B. Cornier, R. Schumacker, A. Vanderpoorten et H. Vannerom. Jardin botanique national de Belgique, Meise. CXXXIX + 1195 pp. ISBN : 9789072619884.
• MNHNL, iNaturalist & GBIF, 2020. Fallopia ×bohemica in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2020-03-02]
• Pfeiffenschneider, M., 2007. Über die Verbreitung von Heracleum mantegazzianum, Impatiens glandulifera, Fallopia japonica und F. sachali­nensis entlang der Gewässer Obersauer, Woltz, Clerve, Wiltz und ihrer Nebengewässer (Luxemburg). Bull. Soc. Nat. luxemb. 108: 7-10. [PDF 400 KB]
• Pfeiffenschneider, M., P. Gräser & C. Ries, 2014. Distribution of selected neophytes along the national railway network of Luxembourg. Bull. Soc. Nat. luxemb. 115: 95-100. [PDF 1457 KB]
• Pfeiffenschneider, M., P. Gräser & C. Ries, 2014. Distribution of selected neophytes along the main rivers of Luxembourg. Bull. Soc. Nat. luxemb. 115: 101-108. [PDF 3668 KB]
• Ries, C. & Y. Krippel, 2021. First records of 56 invasive alien vascular plants in Luxembourg. Bulletin de la Société des naturalistes luxembourgeois 123: 115-127. [PDF 241 KB]
• Ries, C., Y. Krippel & M. Pfeiffenschneider, 2020. Risk assessment after the Harmonia+ protocol of invasive alien vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 122: 197-205. [PDF 132 KB]
• Ries, C., Y. Krippel, M. Pfeiffenschneider & S. Schneider, 2013. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of non-native vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 114: 15-21. [PDF 652 KB]
• Saintenoy-Simon, J. et coll., 2008. Trouvailles floristiques récentes (2006-2007). Adoxa 59: 17-52.

 Page content last updated on 2021-03-04. Last proofread by Caroline Grounds on 2019-11-20.

	Jerusalem artichoke	Status LU: established. 1st record: LU ~1720, ITW <1875.
	Topinambur, Russesch Gromper1	Status Eur.: established. 1st record: UK 1607.
	Topinambour	RA: ISEIA: B2, Watch List. Harmonia+: 0,47.
	Topinambur	Wikipedia: | Wikispecies: | CABI
	Aardpeer	Back to the list of neophytes

Brief description

Helianthus tuberosus between the Alzette river and a maize field near Cruchten (29/06/2016)

Helianthus tuberosus L. is a plant that prefers well-lit, sandy, moist and nutrient-rich soils. It grows best in habitats repeatedly disturbed by floods (riparian areas) but may also occur in ruderal and agricultural environments. In western European climatic conditions, the plant does not produce viable seeds and propagates vegetatively. Tubers and pieces of rhizomes are transported with rodents and flowing water, especially winter floods. The plant can produce dense and persistent monospecific populations along rivers, where it outcompetes native species, slows down natural colonisation by trees and favours river bank erosion. It can be a weed of agricultural fields either by invading the fields or by reducing the yield of consecutive crops.

Introduction in Luxembourg

The Jerusalem artichoke arrived in Luxembourg at the beginning of the 18th century. In his seminal work “La pomme de terre en Wallonie au XVIIIe siècle” (1976), the Belgian historian Fernand Pirotte draws the following conclusions (Pirotte 1976 cit. in Massard 2009):

1. at the beginning of the 18th century, a first previously unknown tuber plant, the Jerusalem artichoke, probably originating from Lorraine, was introduced into the Duchy of Luxembourg under its name “pomme de terre” (earth apple), which was commonly used in Lorraine.
2. around 1715-1720, another tuber plant, the potato, the ‘poire de terre’ or ‘Grundbirne’, was imported from the Rhineland (later the Rhine province) and was called ‘crompire’ or ‘grompir’ by the people.
3. the two species coexisted for some time, with a rapidly increasing dominance of the potato, which overtook Jerusalem artichoke within 20 to 25 years, before 1740. In the 1750s, or at the beginning of the 1760s at the latest, the potato has definitely replaced the Jerusalem artichoke. Paradoxically, the authorities retained the designation “topinambour”, but from about 1740/50 onward they used it for the potato, which they had virtually ignored until then, since its cultivation had been limited to gardens and had thus remained tithe-free.

Status and distribution in Luxembourg

“It seems that the introduction of this tuber, also originating from the New World, dates from the same period as the potato [~1725], and that by the middle of the last century [1750] its cultivation was proportionally more widespread than today” (Fischer 1860: 143; 1872: 77-78). But there may be a confusion of names, as potato cultivation was introduced in the 1720s under the name of topinambour or “ground pear” (De la Fontaine cit. in Fischer 1860: 143).²

In 1741 the tithe (tax) was already raised on the Jerusalem artichoke (Ozeray 1827: 267).

In the middle of the 19th century, “Jerusalem artichokes[…] are so little cultivated in the Grand Duchy that the vast majority of farmers do not yet know its tubers. It is even regrettable that the resources that Jerusalem artichokes can offer in certain circumstances have not yet been fully appreciated” (Fischer 1860: 143).³

Helianthus tuberosus was locally cultivated in Luxembourg throughout the 19th century (Löhr 1844: 126, Fischer 1872: 77), especially around Greisch and Ansembourg castle (Tinant 1836: 434). Krombach (1875: 331) states it is sometimes grown in sandy soils and then occurs also subspontaneously.

The first documented observation of the species in Luxembourg dates from 1880. On 21st October 1880, the Société de botanique collected a specimen from a garden in Dommeldange, north of Luxembourg City (Specimen nr. LUX003675, MNHNL 2000-). The first documented observation of the species in the wild dates from 1956. It was found by Léopold Reichling on 30th September 1956 in Born in the municipality of Mompach (MNHNL 2000-). There are 427 observations in the Recorder-Lux database (MNHNL, iNaturalist & GBIF 2019).

According to Lambinon & Verloove (2012: 720), it grows in banks, gravel and mud banks along watercourses, often in large stands, is naturalised in the Lorraine district (rivers Chiers, Moselle and tributaries (AR), but locally very abundant; elsewhere rare (R), subspontaneous or locally naturalised. Rarely cultivated in gardens, especially in the past, for its edible but generally not very appreciated tubers, nowadays sometimes in fallows, for feeding game.

The Jerusalem artichoke is widely distributed along the Lower Alzette, the Lower Sûre and the Moselle. Along the Alzette, important populations of the species often appear at the edge of corn fields.

Risk assessment

ISEIA protocol

B2 (2+3+2+2) = Watch List (Ries et al. 2013: 18).

Harmonia+ protocol

0,88Invasion
0,53Impact
0,47Risk

Worldwide distribution

Source: https://www.cabi.org/isc/datasheet/26716#toDistributionMaps

Bibliography

• CABI, 2019. Helianthus tuberosus. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-03-02]
• Fischer, E., 1860. Notices historiques sur la situation agricole du grand-duché de Luxembourg. 2e édition, 254 p. Luxembourg : imprimerie Buck.
• Fischer, E., 1872. Les plantes subspontanées et naturalisées de la flore du grand-duché de Luxembourg. Publications de l’Institut royal grand-ducal de Luxembourg, section des sciences naturelles et mathématiques XII: 1-115. Imprimerie V. Buck, Luxembourg.
• Krippel, Y. & G. Colling, 2006. Notes floristiques. Observations faites au Luxembourg (2004-2005). Bull. Soc. Nat. luxemb. 107: 89-103. [PDF 288 Kb]
• Krombach, J.-H.-G., 1875. Flore du grand-duché de Luxembourg. Plantes phanérogames. 564 p. Luxembourg, Imprimerie Joris.
• Lambinon J. & F. Verloove, 2012. Nouvelle flore de la Belgique, du grand-duché de Luxembourg, du Nord de la France et des régions voisines. Sixième édition. Avec la collaboration de L. Delvosalle, B. Toussaint, D. Geerinck, I. Hoste, F. Van Rossum, B. Cornier, R. Schumacker, A. Vanderpoorten et H. Vannerom. Jardin botanique national de Belgique, Meise. CXXXIX + 1195 pp. ISBN : 9789072619884.
• Löhr, M. J., 1844. Taschenbuch der Flora von Trier und Luxemburg : mit Berücksichtigung der Nahe- und Glan-Gegenden. 319 S. Trier, Verlag C. Troschel.
• Massard, J. A., 2009. 300 Jahre Kartoffel in Luxemburg: (I) Europa entdeckt die Kartoffel. (II) Grundbirne, Grompir, Gromper: die Kartoffel erobert Luxemburg. (III) Die Kartoffel in Luxemburg im 19. Jh. Artikel aus: Lëtzebuerger Journal 2009, [I] Nr. 15 (22. Jan.): 23; Nr.16 (23. Jan.): 10, Nr. 17 (24./25. Jan.): 11; [II] Nr. 18 (27. Jan.): 23, Nr. 19 (28. Jan.): 21; [III] Nr. 20 (29. Jan.): 9, Nr. 21 (30. Jan.): 21.
• MNHNL, 2000-. Helianthus tuberosus L. in Recorder-Lux, database on the natural heritage of the Grand Duchy of Luxembourg. Musée national d’histoire naturelle, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-09-05]
• MNHNL, iNaturalist & GBIF, 2019. Helianthus tuberosus L. in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-09-05]
• Ozeray, M.-J.-F., 1827. Histoire des pays, château et ville de Bouillon depuis l’origine du Duché jusqu’à la révolution de 1789. 348 p. Imprimerie J. Lamort, Luxembourg. (1re édition) [online source]
• Pfeiffenschneider, M., P. Gräser & C. Ries, 2014. Distribution of selected neophytes along the main rivers of Luxembourg. Bull. Soc. Nat. luxemb. 115: 101-108. [PDF 3668 KB]
• Pirotte, F., 1976. La pomme de terre en Wallonie au XVIIIe siècle. Liège, Editions du Musée wallon, 87 p. (= Collection d’études publiée par le Musée de la vie wallonne, 4).
• Ries, C. & Y. Krippel, 2021. First records of 56 invasive alien vascular plants in Luxembourg. Bulletin de la Société des naturalistes luxembourgeois 123: 115-127. [PDF 241 KB]
• Ries, C., Y. Krippel, M. Pfeiffenschneider & S. Schneider, 2013. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of non-native vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 114: 15-21. [PDF 652 KB]
• Ries, C., Y. Krippel & M. Pfeiffenschneider, 2020. Risk assessment after the Harmonia+ protocol of invasive alien vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 122: 197-205. [PDF 132 KB]
• Tinant, F. A., 1836. Flore luxembourgeoise, ou, Description des plantes phanérogames, recueillies et observées dans le grand-duché de Luxembourg, classées d’après le système sexuel de Linnée. 512 p. Luxembourg, J. P. Kuborn.

 Page content last updated on 2021-03-04. Last proofread by Caroline Grounds on 2019-11-18.

1. Cf. Krombach 1875: 331.[↩]
2. Original text: « Il faut croire que l’introduction de ce tubercule, aussi originaire du nouveau monde, date de la même époque que la pomme de terre, et que vers le milieu du siècle dernier la culture en était proportionnellement plus répandue qu’aujourd’hui. » (Fischer 1860: 143) Mais il se peut qu’il y ait une confusion de noms, la culture de la pomme de terre ayant été introduite dans les années 1720 sous le nom de topinambour ou poire de terre (De la Fontaine cit. in Fischer 1860: 143).[↩]
3. Original text: « Les topinambours […] sont si peu cultivés dans le Grand-Duché, que l’immense majorité des laboureurs n’y connaissent pas encore ses racines. Il est même à regretter qu’on n’ait pas jusqu’ici apprécié à leur juste valeur les ressources que le topinambour peut offrir dans certaines circonstances » (Fischer 1860: 143).[↩]

	Garden lupin	Status LU: established. 1st record: LU <1901, ITW 1991.
	Gaarde-Luppéng	Status Eur.: established. 1st record: UK 1826.1
	Lupin des jardins	RA: ISEIA: C1. Harmonia+: 0,26.
	Vielblättrige Lupine	Wikipedia: | Wikispecies: | CABI
	Vaste lupine	Back to the list of neophytes

Brief description

The pioneer and ruderal plant Lupinus polyphyllus Lindl. prefers medium-moist and shaded sites, with a nutrient-poor sandy or loamy soil. It is found in riparian habitats, abandoned grasslands, forest clearings, clearcuts and on road verges. The strong invasion of semi-natural habitats, as it can be seen in Scandinavia for example, has so far been reported only rarely in western Europe. Seeds are dispersed in the immediate vicinity of the mother plant.

L. polyphyllus may occur in extensive, rather dense stands. It reduces the diversity of early successional plant communities, but has little effect on later successional stages. In central Europe, the plant replaces species-rich dry acidic grasslands with monocultures. Due to the nitrogen-fixing nodules it may change the soil chemistry in favour of nitrogen-demanding species; eutrophication of nutrient-poor sites and consequent changes in community structure and diversity is the main problem when it invades an area (Branquart et al. 2010).

Status and distribution in Luxembourg

Lupinus polyphyllus Lindl. was first mentioned at a meeting of the Luxembourg Naturalist Society on 1901-05-19 in Diekirch: “Mr. Klein ² shows: (1) a specimen of Lupinus polyphyllus, a perennial plant that overwinters and, because it is very rich in nitrogen, is most suitable for green manure. […]” (Bricher 1901: 179).

The oldest herbarium specimen at the Museum was collected in June 1949 by Jos. Witry in a garden in Bergem (Specimen № 51392, MNHNL 2000-).

Lupinus polyphyllus Lindl. was first documented in the wild in Luxembourg by Yves Krippel (1992) in the forest Bambësch in Luxembourg City. The species was next documented in the wild by Guy Colling on 2002-06-15 during the Biodiversity Weekend 2002 in the municipality of Bettembourg (MNHNL 2000-).

While only few records of the species were listed in the MNHNL-mdata online portal (MNHNL, iNaturalist & GBIF 2019) a few years ago, more and more occurences of L. polyphyllus have been documented recently.

The melliferous garden lupin originates from western North America. Under the name of Lupinus polyphyllus several species, hybrids or cultivars may be confused; next to L. polyphyllus s. str., characterised by the entire upper lip of the calyx, one could observe L. perennis L., L. nootkatensis Donn ex Sims and L. ×regalis Bergm. (L. arboreus Sims × polyphyllus), recognisable by the emarginated upper lip of the calyx (Lambinon & Verloove 2012: 392).

Risk assessment

ISEIA protocol

C1 (1+2+2+2) (Ries et al. 2013: 18).

Harmonia+ protocol

0,55Invasion
0,47Impact
0,26Risk

Worldwide distribution

Source: https://www.cabi.org/isc/datasheet/31710#toDistributionMaps

Bibliography

• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum, F. Verloove & A. Vervoort, 2010. Harmonia database: Lupinus polyphyllus Lindl.. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-11]
• Bricher, E., 1901. Wanderversammlung in Diekirch am 19. Mai. Bulletin de la Société des Naturalistes Luxembourgeois 11 (6): 178-183.
• CABI, 2021. Lupinus polyphyllus. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2021-03-04]
• Krippel, Y., 1992. Effets à court terme d’un apport de fertilisants sur la forêt du Bambësch (Luxembourg-Ville). Travail de fin d’études d’Ingénieur agronome à l’Université Libre de Bruxelles (ULB), section interfacultaire d’agronomie, orientation agronomie générale. [mémoire non publié].
• Lambinon J. & F. Verloove, 2012. Nouvelle flore de la Belgique, du grand-duché de Luxembourg, du Nord de la France et des régions voisines. Sixième édition. Avec la collaboration de L. Delvosalle, B. Toussaint, D. Geerinck, I. Hoste, F. Van Rossum, B. Cornier, R. Schumacker, A. Vanderpoorten et H. Vannerom. Jardin botanique national de Belgique, Meise. CXXXIX + 1195 pp. ISBN : 9789072619884.
• MNHNL, 2000-. Lupinus polyphyllus Lindl. in Recorder-Lux, database on the natural heritage of the Grand Duchy of Luxembourg. Musée national d’histoire naturelle, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-10-11]
• MNHNL, iNaturalist & GBIF, 2019. Lupinus polyphyllus Lindl. in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-10-11]
• Ries, C. & Y. Krippel, 2021. First records of 56 invasive alien vascular plants in Luxembourg. Bulletin de la Société des naturalistes luxembourgeois 123: 115-127. [PDF 241 KB]
• Ries, C., Y. Krippel & M. Pfeiffenschneider, 2020. Risk assessment after the Harmonia+ protocol of invasive alien vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 122: 197-205. [PDF 132 KB]
• Ries, C., Y. Krippel, M. Pfeiffenschneider & S. Schneider, 2013. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of non-native vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 114: 15-21. [PDF 652 KB]

 Page content last updated on 2022-06-14. Last proofread by Caroline Grounds on 2019-11-19.

1. Cf. CABI 2021.[↩]
2. Ed.: Edmond Joseph Klein (1866-1942)[↩]

	Oregon-grape	Status LU: established. 1st record: LU 1842, ITW <1875.
	Gewéinlech Mahonie	Status Eur.: established. 1st record: 1822.1
	Mahonia faux houx	RA: ISEIA: B1 – Watch List. Harmonia+: 0,35.
	Gewöhnliche Mahonie	Wikipedia: | Wikispecies: | CABI
	Mahonie	Back to the list of neophytes

Brief description

The shrub Mahonia aquifolium (Pursh) Nutt. (Syn.: Berberis aquifolium Pursh.) occurs in a wide range of semi-natural habitats like dunes, rock outcrops, grasslands and woodlands. They prefer calcic soils and can grow in dry to moist conditions, often in shaded habitats. Mahonia produces numerous flowers and berries that are dispersed by birds over long distances. The recent expansion of this species in western Europe is probably triggered by climate warming.

Mahonia aquifolium has a high growth rate due to hybridisation and subsequent selection by breeders. Rapid clonal growth takes place through root suckers and stem layering, leading to the formation of large and dense populations that are known to overgrow and outcompete native species and accelerate the colonisation of open habitats by woody vegetation (Branquart et al. 2010).

Status and distribution in Luxembourg

Mahonia aquifolium (Pursh) Nutt. is a common ornamental plant in Luxembourg which regularly escapes from cultivation in private and public gardens to form spontaneous woody vegetation. While documented occurrences in the wild remained rare until a few years ago the actual distribution map seems to indicate that uncultivated populations of the species are much more common now.

Koltz (1875:18) reports that the species was introduced into the Walferdange Park in 1842 (= 1st record); furthermore, it sometimes occurs subspontaneously, e.g. in the fir grove above the Jewish cemetery in Clausen (Luxembourg City), which is why we consider <1875 as the date of 1st record in the wild.

It was next documented in the wild in Luxembourg on 1950-07-20 by Léopold Reichling (1921-2009) in Verluerekascht (Municipality of Larochette) (MNHNL 2000-).

The oldest herbarium specimen at the MNHNL was collected by Jos. Witry on 1935-04-21 in a park in Bergem (Specimen № 51941, MNHNL 2000-).

The melliferous Oregon-grape originates from North America (Lambinon & Verloove 2012: 92).

Other Mahonia species, cultivars and hybrids

Various cultivars and hybrids of this species are planted for ornamental purposes, the latter resulting from hybridisation with other North American species Mahonia pinnata (Lag.) Fedde and M. repens (Lindl.) D. Don in particular. The following taxa could thus be observed escaping from culture: M. aquifolium, M. ×wagneri (Jouin) Rehd. (M. aquifolium × pinnata) and M. ×decumbens Stace (M. aquifolium × repens) (Lambinon & Verloove 2012: 92).

Krombach (1875: 38) mentions Mahonia repens (Lindl.) G.Don for Luxembourg: “Introduced from America and cultivated for its early flowering and evergreen foliage.”

In total, Jean-Pierre-Joseph Koltz (1875: 18) mentions six Mahonia species introduced to Luxembourg:

• Mahonia aquifolium (Pursh) Nutt.: introduced into the Walferdange Park in 1842;
• Mahonia fascicularis DC.: introduced into the Walferdange Park in 1842;
• Mahonia fortunei (Lindl.) Fedde: introduced into the Dominican Park in 1853;
• Mahonia japonica (Thunb.) DC.: introduced into the Dominican Park in 1854;
• Mahonia nervosa (Pursh) Nutt.: introduced into the Dominican Park in 1861;
• Mahonia repens (Lindl) G. Don: introduced into the Walferdange Park in 1842.

Risk assessment

ISEIA protocol

B1 (3+2+2+2) = Watch List (Ries et al. 2013: 18). Because of the growing number of documented observations the ISEIA evaluation should probably be changed to B2.

Harmonia+ protocol

0,72Invasion
0,48Impact
0,35Risk

Worldwide distribution

Source: https://www.cabi.org/isc/datasheet/32269#toDistributionMaps

Bibliography

• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum, F. Verloove & A. Vervoort, 2010. Harmonia database: Mahonia aquifolium (Pursh) Nutt.. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-11]
• CABI, 2021. Mahonia aquifolium. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2021-03-04]
• Koltz, J.-P.-J., 1875. Dendrologie luxembourgeoise. Catalogue des arbres, arbrisseaux et arbustes spontanés, subspontanés ou introduits dans la culture du Grand-Duché de Luxembourg. Imprimerie V. Buck, Luxembourg, 217 pp.
• Krombach, J.-H.-G., 1875. Flore du grand-duché de Luxembourg. Plantes phanérogames. 564 p. Luxembourg, Imprimerie Joris.
• Lambinon J. & F. Verloove, 2012. Nouvelle flore de la Belgique, du grand-duché de Luxembourg, du Nord de la France et des régions voisines. Sixième édition. Avec la collaboration de L. Delvosalle, B. Toussaint, D. Geerinck, I. Hoste, F. Van Rossum, B. Cornier, R. Schumacker, A. Vanderpoorten et H. Vannerom. Jardin botanique national de Belgique, Meise. CXXXIX + 1195 pp. ISBN : 9789072619884.
• MNHNL, 2000-. Mahonia aquifolium (Pursh) Nutt. in Recorder-Lux, database on the natural heritage of the Grand Duchy of Luxembourg. Musée national d’histoire naturelle, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-10-11]
• MNHNL, iNaturalist & GBIF, 2019. Mahonia aquifolium (Pursh) Nutt. in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-10-11]
• Ries, C. & Y. Krippel, 2021. First records of 56 invasive alien vascular plants in Luxembourg. Bulletin de la Société des naturalistes luxembourgeois 123: 115-127. [PDF 241 KB]
• Ries, C., Y. Krippel & M. Pfeiffenschneider, 2020. Risk assessment after the Harmonia+ protocol of invasive alien vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 122: 197-205. [PDF 132 KB]
• Ries, C., Y. Krippel, M. Pfeiffenschneider & S. Schneider, 2013. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of non-native vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 114: 15-21. [PDF 652 KB]

 Page content last updated on 2023-05-05. Last proofread by Caroline Grounds on 2019-11-19.

1. Cf. CABI 2021.[↩]