Japanese rose	Status LU: established. 1st record: LU <1923, ITW 2002.
	Geradderegt Rous	Status Eur.: established. 1st record: 1796.1
	Rosier rugueux	RA: ISEIA: C1. Harmonia+: 0,18.
	Kartoffel-Rose	Wikipedia: | Wikispecies: | CABI
	Rimpelroos	Back to the list of neophytes

Brief description

Rosa rugosa Thunb. is a predominantly coastal shrub species, which grows on dunes, in grasslands and healthlands but also in coastal woodlands. However, it can grow further inland, where it can be found in fields, boreal forest, disturbed areas, grasslands, heathlands, riparian zones, temperate broadleaf forest and in urban areas. Open dry grasslands, as well as heathlands, especially those with bare patches, are potentially in danger of an invasion by R. rugosa. The species also occurs in various open ruderal habitats like road verges, railway embankments or waste ground (garden escape), but appears to grow less vigorously there.

Rosa rugosa forms extensive impenetrable thickets due to root and stem suckering. It displaces the natural flora of beach and dune vegetation and outcompetes early successional plant species in these habitats (Arenaria serpyllifolia, Empetrum nigrum, Festuca rubra, Veronica arvensis, Viola tricolor, etc.). Thickets of R. rugosa are species-poor, irrespective of the dune type on which the shrub has established. They change humus conditions, favour the installation of other neophytes like Lupinus polyphyllus and Parthenocissus inserta and alter habitat structure through shading effect and initiation of dune formation. They may also act as a reservoir for potential pest species like gall-forming insects. Hybrids with native Rosa species occur (Branquart et al. 2010).

Status and distribution in Luxembourg

Rosa rugosa Thunb. is commonly planted in public green areas and private gardens in Luxembourg since a long time, as documented in old newspapers (Anonym 1923): “Large-fruited rosehips Rosa rugosa and Rosa villosa are popular rosehip varieties for conserving.”² We thus consider the first record of Rosa rugosa as cultivated species to be anterior to 1923.

Rosa rugosa Thunb. was first documented in the wild by Guy Colling on 15th June 2002 in the Stréissel nature reserve, north of the municipality of Bettembourg (MNHNL 2000-).

Currently, 15 records of Japanese rose are accessible through the MNHNL-mdata portal (MNHNL, iNaturalist & GBIF 2019).

The east Asian melliferous species is often cultivated for ornamental purposes in parks and along roadsides. Subspontaneous or naturalised: coastal dunes, roadsides, embankments, stream banks, especially in the west (Lambinon & Verloove 2012: 362).

Risk assessment

ISEIA protocol

C1 (1+1+1+1) (Ries et al. 2013: 19).

Harmonia+ protocol

0,45Invasion
0,38Impact
0,18Risk

Worldwide distribution

Source: https://www.cabi.org/isc/datasheet/47835#toDistributionMaps

Bibliography

• Anonym, 1923. Hof, Garten, Land. Praktische Winke für den Kleingärtner und Tierhalter für den Monat April. Rubrik. Obermosel-Zeitung 55: 2 (1923-04-07).
• Branquart Etienne, Vanderhoeven Sonia, Van Landuyt Wouter, Van Rossum Fabienne, Verloove Filip
• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum & F. Verloove, 2010. Harmonia database: Rosa rugosa Thunb.. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-15]
• CABI, 2019. Rosa rugosa. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-03-02]
• 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-. Rosa rugosa Thunb. 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 2019-10-15]
• MNHNL, iNaturalist & GBIF, 2019. Rosa rugosa Thunb. 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 2019-10-15]
• 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. Bulletin de la Société des naturalistes luxembourgeois 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. Bulletin de la Société des naturalistes luxembourgeois 114: 15-21. [PDF 652 KB]

 Page content last updated on 2021-03-11. Last proofread by Caroline Grounds on 2019-11-21.

1. Cf. CABI 2019.[↩]
2. Original on a-z.lu: Großfrüchtige Hagebutten Rosa rugosa und Rosa villosa sind beliebte Hagebuttensorten zum Einmachen.[↩]

	Small balsam	Status LU: established. 1st record: LU & ITW 1956.
	Klengt Sprangkraut	Status Eur.: established. 1st record CH: <1831.1
	Balsamine à petites fleurs	RA: ISEIA: C3. Harmonia+: 0,13.
	Kleines Springkraut	Wikipedia: | Wikispecies: | CABI
	Klein springzaad	Back to the list of neophytes

Brief description

Impatiens parviflora DC. is an annual herb that is widely dispersed in European forests. It prefers shaded and moist nutrient-rich stands, but can also grow in acidic conditions. It thrives in beech and alder forests, but can also be found in parks, along hedgerows, on forest edges, in waste grounds and ruderal habitats (Branquart et al. 2010).

Status and distribution in Luxembourg

Impatiens parviflora DC. was first documented by Jean-Jacques Kariger (1925-2018) in late June 1956 in an alluvial forest along the Attert, downstream of Redange (Reichling 1958, Specimen № 24952, MNHNL 2000-, Krippel & Proess 2017: 57).

456 records of the species are listed in the MNHNL-mdata online portal and the plant is widespread throughout the country’s forests (MNHNL, iNaturalist & GBIF 2019). Most of these data have been collected during systematic inventories along the main watercourses in 2013 (Pfeiffenschneider et al. 2014).

This annual plant species from central and eastern Asia is naturalised in a large part of Europe (Lambinon & Verloove 2012: 480).

Alien Impatiens taxa

Six alien balsam species have been reported in Luxembourg, Impatiens noli-tangere L. being the only native species.

• Impatiens balfourii Hook.f.: Balfour’s touch-me-not, first observed in 2016 in the wild in Luxembourg.
• Impatiens balsamina L.: the garden balsam is already mentioned in Krombach’s flora of 1875 as “Introduced from the East Indies and grown in all gardens” (Krombach 1875: 56).
• Impatiens capensis Meerb. is an annual plant native to eastern North America that is currently spreading across Europe. In Luxembourg, it was first reported on 2021-10-11 from the Moselle valley.
• Impatiens glandulifera Royle: the invasive Himalayan Balsam, which is widespread in riparian ecosystems and forests across Luxembourg.
• Impatiens parviflora DC.: the small balsam, which is widespread in forests across Luxembourg.
• Impatiens walleriana Hopok. f. was reported once as cultivated in Rumelange in 1946.

In 2011 the annual hybrid Impatiens parviflora × I. balfourii was discovered in the canton of Ticino in Switzerland. The fertile hybrid with alternating leaves can be up to 60 cm high. Considerable populations of the hybrid were observed in 2014 in the canton of Ticino in the absence of the parent species (Van Valkenburg et al. 2019).

Risk assessment

ISEIA protocol

C3 (3+2+1+1) (Ries et al. 2013: 18).

Harmonia+ protocol

0,63Invasion
0,20Impact
0,13Risk

Worldwide distribution

Source: https://www.cabi.org/isc/datasheet/28768#toDistributionMaps

Bibliography

• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum, F. Verloove & A. Vervoort, 2010. Harmonia database: Impatiens parviflora DC. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-09]
• CABI, 2021. Impatiens parviflora. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2021-03-04]
• Krippel, Y. & R. Proess, 2017. Impatiens balfourii Hook. f. (Balsaminaceae), nouvelle espèce subspontanée au Luxembourg ?. Bull. Soc. Nat. luxemb. 119: 55-61.
• 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-. Impatiens parviflora DC. 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. Impatiens parviflora DC. 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]
• 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]
• Reichling, L., 1958. Notes floristiques – Observations faites dans le grand-duché de Luxembourg en 1956. Bull. Soc. Nat. luxemb. 61: 63-123. [PDF 3355 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]
• Van Valkenburg, J. L. C. H., N. Schoenenberger, B. T. L. H. van de Vossenberg, W. A. Man in’t Veld, M. Westenberg & E. Boer, 2019. A natural hybrid of Impatiens, in the introduced range, demonstrated by sequence analysis of the nuclear ribosomal DNA-gene repeat. Botany Letters 166: 144-152.

 Page content last updated on 2021-12-10. Last proofread by Caroline Grounds on 2019-11-19.

1. Cf. CABI 2021.[↩]

	Butterfly-bush, summer lilac	Status LU: established. 1st record: LU & ITW 1961.
	Päiperlekstrausch	Status Eur.: established. 1st record: FR 1893.
	Buddleia de David	RA: ISEIA: C2. Harmonia+: 0,41
	Schmetterlingsflieder, -strauch	Wikipedia: | Wikispecies: | CABI
	Vlinderstruik	Back to the list of neophytes

Brief description

Buddleja davidii Franch. is a shade-intolerant woody melliferous species. The deciduous shrub mostly thrives in various ruderal areas and disturbed grounds, which it colonises rapidly, but also grows in warm semi-natural habitats with well-drained soils like gravel shores, rock outcrops or open woodlands. Climate change is likely to trigger higher invasiveness in Europe during the next decades (Branquart et al. 2010). It often blooms as soon as it reaches a few tens of centimetres in height (Lambinon & Verloove 2012: 535).

Buddleja davidii was introduced as a horticultural plant to Europe in the 1890ies and naturalized on a significant scale in the 1930s in parts of Europe, after the destruction of cities during World War II. Bombed sites and building rubble were suitable colonization habitats and therefore dense B. davidii thickets established on these sites. In the 1950s and 1960s, B. davidii became a popular garden shrub, which further contributed to its spread when it escaped from cultivation and naturalized in the wild (CABI 2019).

Status and distribution in Luxembourg

In Luxembourg, Buddleja was first documented in the wild by Léopold Reichling on 1961-05-02 in Luxembourg City (Grund, Verluerekascht). As only one species of Buddleja occurs in the territory of the Flore (Lambinon & Verloove 2012: 535), we can assume that Reichling reported Buddleja davidii. In the following year, Reichling found summer lilac on 1962-06-06 near Schleifmuehle upstream from Medernach.

The next observation in the wild was reported by Gérard Schmidt on 1993-08-05 in the gravel quarries of Remerschen near Wintrange, Municipality of Schengen (Schmidt 1993; MNHNL 2000-). More than 140 observations of the butterfly-bush are documented in the data portal of the Museum (MNHNL, iNaturalist & GBIF 2020).

Summer lilac is widely cultivated in gardens across Luxembourg, from where it can easily make its way into the wild. The distribution map for Luxembourg shows that the species occurs most frequently in the south of the country, while less observations of Buddleja davidii in the wild exist for the Oesling.

A survey along the national railway network of Luxembourg revealed that summer lilac is spreading along the railway tracks in the South West of the country and in the Moselle valley (Pfeiffenschneider et al. 2014a).

Buddleja davidii has been spreading continuously in recent years, especially in urban environments, on rocks and railways (Krippel et al. 2018: 60-61). The butterfly-bush is still expanding its distribution area and increasingly found in urban wastelands (Krippel et al. 2020: 34).

The first observation of this species in its subspontaneous state in Belgium and northern France dates back to 1940. It spread mainly from the 1970s onwards (Lambinon & Verloove 2012: 535).

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

Risk assessment

ISEIA protocol

C2 (2+2+2+2) (Ries et al. 2013: 18).

Harmonia+ protocol

0,81Invasion
0,50Impact
0,41Risk

Worldwide distribution

Source: https://www.cabi.org/isc/datasheet/10314#toDistributionMaps

Bibliography

• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum, F. Verloove, 2010. Harmonia database:Buddleja davidii Franch. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-02]
• CABI, 2019. Buddleja davidii. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2021-02-26]
• Krippel, Y., T. Helminger & G. Colling, 2018. Notes floristiques. Observations faites au Luxembourg (2016-2017). Bull. Soc. Nat. luxemb. 120: 57-76. [PDF 265 KB]
• 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]
• 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-. Buddleja davidii Franch. 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 2020-01-12]
• MNHNL, iNaturalist & GBIF, 2019. Buddleja davidii Franch. 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 2019-09-06]
• Pfeiffenschneider, M., P. Gräser & C. Ries, 2014a. 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, 2014b. 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]
• Schmidt, G., 1993. Fiches de terrain, cartographie des biotopes de la commune de Remerschen. Fondation Oeko-Fonds, Luxembourg. Non published document.

 Page content last updated on 2023-08-17.

	Confused Michaelmas-daisy	Status LU: established. 1st record: LU & ITW <1872.
	Neibelsch Aster	Status Eur.: established. 1st record: 1710, ITW 1865.
	Aster de viriginie	RA: ISEIA: C1. Harmonia+: 0,08
	Neubelgische Aster	Wikipedia: | Wikispecies: | CABI
	Nieuw-Nederlandse aster	Back to the list of neophytes

Brief description

Aster novi-belgii L. thrives mostly in ruderal and waste areas, especially on rich and moist soils. It is less often observed in riparian habitats than other North American asters. The plant mainly spreads vegetatively and through fly-tipping of green waste and waste grounds. Seeds do not seem to be able to maturate under Belgian climatic conditions.¹

Asters are rhizomatous species, propagating clonally. They easily form dense and wide monospecific colonies, displacing native wetland plants, and favouring the sedimentation and stabilisation of riverbanks, which reduces the ability of rivers to meander and flood (Branquart et al. 2010).

Status and distribution in Luxembourg

Back in 1872, Eugène Fischer listed the species under its synonym Aster floribundus Willd.: “This plant, with a very apparent and late flowering, is often and vulgarly cultivated for the decoration of gardens and especially cemeteries, where it still flowers during the All Saints’ Day period. Many of our cemeteries are teeming with them. It spreads easily and is maintained with persistence. It is frequently found subspontaneously in hedges around homes, gardens and cemeteries. It is so common in the surroundings of Luxembourg that I have often been surprised that Tinant [1836] and the authors of the local flora do not mention it. It is therefore a very modern introduction. It is of American origin” (Fischer 1872: 83).²

Both Koltz (1873: 129; 1874: 30) and Krombach (1875: 345) reiterate it grows in cemeteries, gardens and often subspontaneously in the vicinity of dwellings.

On the 12th November 1906, Félix Heuertz collected Aster novi-belgii ssp. eu-novi-belgii var. tardiflorus on the Prussian riverside across Echternach (Specimen № 13911, MNHNL 2000-a).

The first documented observation of the species in Luxembourg dates from 1949. On 12th September 1949, François Léon Lefort (1917-1975) collected a specimen of Aster novi-belgii ssp. laevigatus (Lam.) Thell. pro parte on the Moselle river bank in Schengen (Specimen № 26905, MNHNL 2000-a).

According to Lambinon & Verloove (2012: 706), the species is rare to very rare (R-RR) around villages, vacant lots, wastelands, and river banks.

Currently, 14 records of the species and its subspecies are accessible through the MNHNL-mdata portal (MNHNL, iNaturalist & GBIF 2019).

Other Aster taxa

1. Aster dumosus L. (Syn.: Symphyotrichum dumosum (L.) G. L. Nesom): the bushy aster is first reported by Tinant on the banks of the Moselle (Wirtgen 1842: 89; Lefort 1950: 41). A hybrid Aster dumosus x novi-belgii was collected by Paul Grzonka and Léopold Reichling on 29 September 1959 in Bech-Kleinmacher in the Moselle valley (MNHNL 2000-b).
2. Aster lanceolatus Willd.: the narrow-leaved Michaelmas-daisy was first collected by Jos. Witry on 24th August 1934 in Grevenmacher in the Moselle valley (MNHNL, iNaturalist & GBIF 2019).
3. Aster ×salignus: this hybrid between A. lanceolatus x A. novi-belgii is much confused with both its parents, particularly A. lanceolatus. The common michaelmas daisy was first mentioned by Yves Krippel in 2001 at Pällembierg (MNHNL 2000-b).

Risk assessment

ISEIA protocol

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

Harmonia+ protocol

0,31Invasion
0,30Impact
0,08Risk

Worldwide distribution

Source: https://www.cabi.org/isc/datasheet/7557#toDistributionMaps

Bibliography

• Beck, E., Jungblut, F., Lefort, F.L., Reichling, L., Stumper, R., 1952. Herborisations faites au Grand-Duché de Luxembourg en 1951. Bull. Soc. Nat. luxemb. 56: 67-88. [PDF 1080 KB]
• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum & F. Verloove, 2010. Harmonia database: Aster novi-belgii L. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-23]
• CABI, 2016. Aster novi-belgii [original text by Ilias Travlos]. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-02-28]
• 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.
• Koltz, J.-P.-J., 1873. Prodrome de la flore du grand-duché de Luxembourg. Première partie. Plantes phanérogames. Imprimerie V. Buck, Luxembourg. 279 S.
• Koltz, J.-P.-J., 1874. Plantes phanérogames découvertes dans le Grand-Duché depuis la publication de la flore luxembourgeoise de Tinant (1836). Recueil des mémoires et des travaux publiés par la Société de botanique du grand-duché de Luxembourg 1: 12-39.
• 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.
• Lefort, F. L., 1950. Contribution à l’histoire botanique du Luxembourg (av. 18 planches). Bull. Soc. Nat. luxemb. 54: 31-160. [PDF 6781 KB]
• MNHNL, 2000-a. Aster novi-belgii 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 2019-09-03]
• MNHNL, 2000-b. 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 2019-10-24]
• MNHNL, iNaturalist & GBIF, 2019. Aster novi-belgii 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 2019-09-06]
• 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]
• Wirtgen, P., 1842. Prodromus der Flora der preussischen Rheinlande. Henry & Cohen, Bonn. 242 p.

 Page content last updated on 2021-03-02. Last proofread by Caroline Grounds on 2019-11-13.

1. The same should apply under Luxembourgian climate.[↩]
2. Original text: « Cette plante, à floraison très-apparente et tardive, est souvent et vulgairement cultivée pour l’ornementation des jardins et surtout des cimetières, où elle fleurit encore à l’époque de la Toussaint. Beaucoup de nos cimetières en fourmillent. Elle se propage avec facilité et se maintient avec persistence. On la rencontre fréquemment subspontanée dans les haies aux environs des habitations, des jardins et des cimetières. Elle est si commune dans les environs de Luxembourg, que je me suis souvent étonné de ce que Tinant et les auteurs des flores locales n’en font pas mention. Elle est donc d’introduction très moderne. Elle est d’origine américaine » (Fischer 1872: 83).[↩]

	Ashleaf maple	Status LU: established. 1st record: LU <1825, ITW <1875
	Eschen-Äerchen	Status Eur.: established. 1st record: UK 1688
	Erable negundo	RA: ISEIA: C1. Harmonia+: 0,23
	Eschen-Ahorn	Wikipedia: | Wikispecies: | CABI
	Vederesdoorn	Back to the list of neophytes

Brief description

Acer negundo L. is reported to prefer moist, eutrophic and warm conditions. It readily colonises resource-rich riparian forests in Central and Southern Europe (e.g. Salicion albae and Alno-Padion). Young trees prefer moist sites, but become drought tolerant once well established. Seeds are easily dispersed by wind and running water over long distances.

In Central Europe, box-elder is tolerant to flooding and is especially competitive in wide floodplains where vegetative regrowth can be impressive. However, in the absence of flooding, it is usually replaced in the course of succession by more shade-tolerant species. In optimal conditions, its permanent and fast vegetative regrowth leads to the formation of dense clones and to the exclusion of other tree species (Salix alba) and herbaceous plants. It favours replacement of softwood by hardwood tree species and makes a threat for this endangered habitat. A more invasive behaviour is likely to be observed in the future due to climate warming (Branquart et al. 2010).

Status and distribution in Luxembourg

The who oldest reference to Acer negundo L. in Luxembourg are found in the floras of Krombach and Koltz: Krombach (1875: 66) reports it being grown in parks and avenues, while Koltz (1875:  27) mentions Acer negundo as “Introduced at the beginning of this century under the name of green maple [Orig.: érable vert] and subspontaneous in the vicinity of Ansembourg”. We thus deduct the 1st record as anterior to 1825 and the 1st record in the wild as anterior to 1875 (Ries & Krippel 2021).

Acer negundo as a cultivated species was first recorded in 1948 by Jos. Witry in a park in Rumelange (Specimen № 51452, MNHNL 2000-).

The first documentation of Acer negundo in the wild dates from 1958. It was recorded on 1st June 1958 by Léopold Reichling at Stromberg, a wooded hill in the municipality of Schengen (MNHNL 2000-).

14 observations are accessible via the MNHNL-mdata portal (MNHNL, iNaturalist & GBIF 2019).

The species is expanding into the territory of the flora (Lambinon & Verloove 2012: 461).

Risk assessment

ISEIA protocol

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

Harmonia+ protocol

0,53Invasion
0,43Impact
0,23Risk

Worldwide distribution

CABI 2019: https://www.cabi.org/isc/datasheet/2862#toDistributionMaps

Bibliography

• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum & F. Verloove, 2012. Harmonia database: Acer negundo L. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-23]
• CABI, 2019. Acer negundo L. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2019-11-26]
• 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-. Acer negundo 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 2018-01-08]
• MNHNL, iNaturalist & GBIF, 2019. Acer negundo 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 2019-09-06]
• 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 2021-03-02. Last proofread by Caroline Grounds on 2019-11-12.

	Common Ragweed	Status LU: established. 1st record: LU 1949, ITW 1950.
	Alzem-Ambrosia	Status Eur.: established. 1st record: NL 1860.
	Ambroisie à feuilles d’armoise	RA: ISEIA: C1. Harmonia+: 0.54
	Beifußblättriges Traubenkraut, Ambrosia	Wikipedia: | Wikispecies: | CABI
	Alsemambrosia	Back to the list of neophytes

Brief description

Ambrosia on a private parking spot in Dalheim (08/07/2015).

Ambrosia artemisiifolia L. is an opportunistic and ruderal plant that colonises farmlands, fallow lands and road embankments. Ambrosia prefers warm areas and light, nutrient-rich soil deprived of vegetation. The common ragweed is unlikely to outcompete other plant species as it mainly colonises soil without vegetation. It is a public health hazard as it commonly causes allergies (rhinitis, asthma…) and is a weed in cereal fields (Branquart et al. 2010).

Status and distribution in Luxembourg

In Luxembourg, the first documentation of Ambrosia artemisiifolia L. dates from 1949. It was found on 6th October 1949 in a garden in Helmsange (Municipality of Walferdange) and determined as Ambrosia elatior L. (synonym) by the Belgian botanist André Lawalrée (Beck et al. 1950).

The species was next recorded in the wild by Léopold Reichling (1921-2009) on 5 September 1950 in a waste ground in Neudorf, Luxembourg City (Obs. key: DSS004390000166M, MNHNL 2000-).

Nowadays, the species is considered as quite rare to rare (AR-R), expanding in the territory of the flora (Lambinon & Verloove 2012: 716).

Luxembourg belongs to one of the few remaining European areas with a very low distribution of Ambrosia artemisiifolia.

In his diploma thesis, Patrick Thommes (2008) had a closer look at the occurrence of common ragweed in Luxembourg, at its germination rate and its ability to produce viable seeds and at the contamination rate of bird food with Ambrosia seeds.

Contaminated bird food is the main origin of Ambrosia populations in Luxembourg. One large population (0.5 ha) of the plant was accidentally established in Kockelscheuer by a nature conservation organisation a few years ago when seeding a sunflower field for a visitor centre. Measures to eradicate the population have been ongoing since 2012, but show only partial success. Flowering meadow mixtures appear to be a new pathway, having been the source of a population discovered in 2014 in a garden in Wasserbillig.

A large population was discovered on a private parking spot in Dalheim in October 2014 – these plants might originate from seeds transported by car wheels, the owner using the spot being a frequent traveller to France.¹ The population was reported again in 2015 and eradicated right away.²

Steil et al. (2015) looked again at common ragweed seeds in bird food in Luxembourg in 2014 and compared the results with earlier studies by Thommes (2008, 2009), conducted in 2007, and by Ries et al. (2013), conducted in 2012. Between 2007 and 2014, the number of contaminated samples decreased in most types of products.

The Museum represented Luxembourg in an interdisciplinary network of experts involved in the control of ragweed, health care professionals, aerobiologists, ecologists, economists, and atmospheric and agricultural modelers. More than 120 participants from 33 countries were participating in SMARTER (2013-2017), the acronym for Sustainable Management of Ambrosia artemisiifolia in Europe (http://internationalragweedsociety.org/smarter/). SMARTER was a COST project funded by the EU.

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

Risk assessment

ISEIA protocol

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

Harmonia+ protocol

0,54Invasion
1,00Impact
0,54Risk

Worldwide distribution

Source: https://www.cabi.org/isc/datasheet/4691#toDistributionMaps

Fact sheet and leaflet

PDF fact sheet of the Nature and Forestry Administration: FR | DE

In autumn 2016 the Department for the Environment of the Luxembourg Ministry of Sustainable Development and Infrastructures published a leaflet in German and French about Ambrosia artemisiifolia, in co-operation with the National Museum of Natural History and efor-ersa ingénieurs-conseils. It can be downloaded here in PDF format (4 MB each).

Other Ambrosia species

• Ambrosia psilostachya DC. was found in a stone quarry between Bridel and “Croix des Bourgeois” in the summer of 1947 and published under the synonym Ambrosia coronopifolia Torr. & A.Gray (Beck et al. 1950: 204).
• Ambrosia trifida L. was found on rubble in Luxembourg City on 1950-08-17 (Beck et al. 1951: 171).

Bibliography

• Anonymous (2015) Beifussblättrige Ambrosie – Eine invasive Art mit Risiken für Allergiker. Regulus 4/2015: 14-15. [PDF 246 KB]
• Beck, E., Jungblut, F., Lefort, F.L., Reichling, L., Stumper, R., 1950. Herborisations faites dans le Grand-Duché de Luxembourg en 1949 (av. 2 fig. et 7 planches). Bull. Soc. Nat. luxemb. 54: 161-208. [PDF 1745 KB]
• Beck, E., Jungblut, F., Lefort, F.L., Reichling, L., Stumper, R., 1951. Herborisations faites au Grand-Duché de Luxembourg en 1950 (av. 10 planches). Bulletin de la Société des naturalistes luxembourgeois 55: 121-174. [PDF]
• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum & F. Verloove, 2010. Harmonia database: Ambrosia artemisiifolia L. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-23]
• CABI, 2016. Ambrosia artemisiifolia L. [original text by Duilio Iamonico]. 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, iNaturalist & GBIF, 2019. Ambrosia artemisiifolia 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 2020-02-28]
• Ries, C., 2017. Ambrosia artemisiifolia in Luxemburg. PowerPoint-Präsentation. Fachtagung Ambrosiabekämpfung – Rechtliche Rahmenbedingungen und Praxiserfahrungen, 2. Februar 2017, Bayerische Landesregierung, München. [PDF 536 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]
• Ries C, Y Steil & P Thommes (2013) Common ragweed (Ambrosia artemisiifolia L.) seeds in bird food in Luxembourg in 2007 and 2012. Poster. XXXe réunion annuelle des collaborateurs scientifiques du Musée national d’histoire naturelle Luxembourg, 16.03.2013. [PDF 1.5 MB]
• Steil, Y., H. Vetter, P. Thommes & C. Ries, 2015. Ambrosia artemisiifolia L. seeds in bird food in Luxembourg: a comparative study, 2007 to 2014. Bull. Soc. Nat. luxemb. 117: 11-15. [PDF 151 KB]
• Thommes P (2008) Ambrosia artemisiifolia L.: Ein potentiell invasiver Neophyt für Luxemburg. Unpublished diploma thesis. 76 p. [PDF 12 MB]
• Thommes P (2009) Ambrosia artemisiifolia L. (Asteraceae), ein potentiell invasiver Neophyt für Luxemburg. Bull. Soc. Nat. luxemb. 110: 101-107. [PDF 265 KB]

 Page content last updated on 2023-08-17. Last proofread by Caroline Grounds on 2019-11-13.

1. The population was reported on 24 November 2014 by Claudine Gengler via email. PhD student Yan Steil visited the place several times but the owners couldn’t be reached.[↩]
2. After the report of the population by Claudine Gengler via phone in the beginning of July 2015, the following people visited the population and searched the area for further occurrences on July 8th 2015: Christian Ries (MNHNL), Manou Pfeiffenschneider (efor-ersa), Tom Engel (ANF). Mr Engel and his team eradicated the population shortly later. Three plants of 30 cm height were reported by Claudine Gengler on October 14, 2015.[↩]

	Black locust, false acacia	Status LU: established. 1st record: LU 1787, ITW <1836.
	Schäinakazi	Status Eur.: established. 1st record: FR 1602.1
	Robinier faux-acacia, acacia	RA: ISEIA: A3, Black List. Harmonia+: 0,53.
	Gewöhnliche Robinie, Falsche Akazie	Wikipedia: | Wikispecies: | CABI
	Robinia, valse acacia	Back to the list of neophytes

Brief description

Robinia pseudoacacia L. is an early successional plant, preferring full sun, well drained soils, and little competition. It reproduces both from seed and by sprouting from the roots or stump. Although this tree produces abundant seeds, germination rate is often low in our climatic conditions [Belgium]. The area potentially invaded is likely to increase considerably under a warmer climate. Once introduced, the black locust expands readily by root suckering and stump sprouting and forms dense clones creating shaded islands from which most native plants are outcompeted. It also modifies soil properties and favours the development of a nitrogen-demanding vegetation. The large, fragrant blossoms of R. pseudoacacia are sometimes reported to compete with native plants for pollinating bees (Branquart et al. 2015).

The first Black Locust in Europe, still standing on square René-Viviani in Paris, planted by Jean Robin in 1602.

Originally from North America, Robinia pseudoacacia was introduced to Europe at the beginning of the 17th century by Jean Robin (1550-1629), the French court gardener. One of the first European black locust trees, now over 400 years old, is still standing in Paris, near Notre-Dame (Anonymous 2020: 8). It is standing on square René-Viviani and is to date the oldest tree of Paris (Baraton 2021: 353).

Status and distribution in Luxembourg

Tinant (1836: 371) mentions “Robinia Pseudo-Acacia” as a naturalised exotic tree.

In 1860, Eugène Fischer reports that Jean-Mathias de Blochausen brought back several tree species from a journey to Italy in 1669, including false acacia and Italian poplar, the latter for roadside planting (Fischer 1860: 178-181).² Around 1872, according to the same Eugène Fischer (1872: 37-38), “it is frequently and advantageously cultivated on our slopes, poor iridescent marls, in groves, promontories, and it is sometimes even used to make fence hedges. The first Robinia trees planted in the Grand Duchy were imported from Italy around 1669 by a de Blochausen. For more than a century this tree was still rare in the country, since Mr. de la Fontaine, former governor of the Grand Duchy, mentioned, as one of the first subjects of this tree in our country, an acacia tree planted in 1787 by Mr. Baron de Maréchal in the garden dependent on Stadtbredimus castle”.³ (see also: Fontaine 1862: 89; Klein 1897: 432).

This year, 1669, mentioned by Fischer, appears to be an error: the facts related are dated in the wrong century as the Family de Blochausen only arrived in Luxembourg around 1764, when Marie-Gisberte de Blochausen bought the Domaine de Brückenberg in Colmar-berg and Jean-Mathias de Blochausen bought the Rollingen forge. We therefore guess that it should read 1769 instead of 1669, which would also be in line with two reports of first planting in 1787 in Stadtbredimus (Fischer 1872: 37-38) and at Kaaschtel near Altwies (Commune de Mondorf 2013, Wikipedia Luxembourg 2013). So we consider 1787 as the year of first record in Luxembourg until historic research brings new evidence.
One of the oldest black locust trees of Luxembourg can be admired in the village of Tétange, municipality of Kayl. The multi-stem tree has a diameter of 150 cm (Anonymous 2020: 9).

Oldest herbarium specimens at the MNHNL:

• June 1883: Edmond Joseph Klein (1866-1942) collected a specimen in the district Pulvermühl in Luxembourg City (Specimen № 16553, MNHNL 2000-)
• 24 May 1934: J. Witry collected a specimen in Rumelange (Specimen № 51811, MNHNL 2000-)
• 18 May 1952: Marcel Etringer collected a specimen in Groeknapp in Graulinster, municipality of Junglinster (Specimen № 49906, MNHNL 2000-)

1346 records are accessible through the MNHNL-mdata portal (MNHNL, iNaturalist & GBIF 2019).

False acacia is a common ornamental tree in Luxembourg, and also occurs widely in the wild, mostly along roadside slopes and railway lines. The distribution map does not reflect the real distribution in the country: the species is so widespread that it is hardly reported any more. An inventory in 2013 revealed the false acacia to be one of the most common invasive alien vascular plant species along railways (Pfeiffenschneider et al. 2014b).

Until 2013 black locust was not considered an invasive alien species in Luxembourg by the Nature Conservation and Forestry Administration (Administration de la nature et des forêts – ANF).

Miscellaneous

• The false acacia plays a role in honey production in Luxembourg.
• Except for its flowers, black locust is highly poisonous, which is why black locust wood should not be used for grilling (Anonymous 2020: 9).
• Acacia wood is used for various purposes: it is sought after for resistance parts, tool handles, etc. Its leaves provide excellent forage and its flowers are gleaned by bees (Krombach 1875: 115).⁴
• Next to the Kaaschtel, a former oppidum across the French border southeast of Altwies on former Luxembourg territory in Lorraine, France, a few huge and very old individuals of Robinia can be found. A legend says the Lord of Preisch brought them from a pilgrimage to the Holy Land and had them planted in 1787 (Commune de Mondorf 2013, Wikipedia Luxembourg 2013).

Other Robinia cultivars and taxa

• The flowerless cultivar ‘Umbraculifera’ has been cultivated in Luxembourg for a long time (Koltz 1873: 43; 1875) and is quite common all across the country (Welter et al. 2008: 72). A beautiful example can be seen in the court of the National Centre of Literature in Mersch.⁵ Koltz (1873: 43) lists Robinia pseudo-acacia var. umbraculifera Des. as a variety (Fr: Acacien boule). According to Krombach (1875: 115) the cultivar ‘Umbraculifera’ (Fr: Acacia parasol) was grown in gardens under the French names of “Acacia boule” or “Acacia fourrage”.
• Recently there has been an increase in the cultivar ‘Unifoliola’, as more street and alignment trees have been observed (Welter et al. 2008).
• Robinia viscosa Vent., another North American species, is very rare in Luxembourg (Welter et al. 2008).
• Lambinon & Verloove (2012: 392) mention cultivated less spiny and less flowering intraspecific taxa, that can be combined under the name Robinia pseudoacacia var. inermis; furthermore some other pink-flowered representatives of the genus Robinia are sometimes grown for ornamental purposes in parks and especially along avenues, including R. ×ambigua Poiret (R. pseudoacacia × viscosa Vent.) and R. hispida L..
• Koltz (1873: 43) lists Robinia viscosa Vent. (Fr: Acacien [sic!] rose). Krombach (1875: 115) mentions R. viscosa with viscous branches and pink flowers in short bunches.

Risk assessment

ISEIA protocol

A3 (2+3+3+3) = Black List (Ries et al. 2013: 19).

Harmonia+ protocol

0,89Invasion
0,60Impact
0,53Risk

Worldwide distribution

Source: https://www.cabi.org/isc/datasheet/47698#toDistributionMaps

Bibliography

• Anonymous, 2020. Baum des Jahres 2020: Die Robinie. Regulus 5 (2020): 8-9.
• Baraton, A., 2021. Dictionnaire amoureux des arbres. Plon. 438 pp.
• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum & F. Verloove, 2015. Harmonia database: Robinia pseudoacacia L. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-23]
• CABI, 2019. Robinia pseudoacacia. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-03-02]
• Commune de Mondorf, 2013. Le Castel – De Kaaschtel. URL: http://www.mondorf.info/index.php?option=com_content&view=article&id=17&Itemid=86&lang=fr [2013-09-27].
• 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.
• Fontaine, G.T. I. de la, 1862. Robinier – Acacia. Bull. Soc. sci. nat. g.-d. Luxemb. 5 (1857-1862): 89.
• Klein, E. J., 1897. Die Flora der Heimat (sowie die hauptsächlichsten bei uns kultivierten fremden Pflanzenarten biologisch betrachtet. Eine Anleitung zur selbständigen Beobachtung der Lebens- und Anpassungserscheinungen in der Pflanzenwelt). 552 S., Buchdruckerei Justin Schroell, Diekirch.
• Koltz, J.-P.-J., 1873. Prodrome de la flore du grand-duché de Luxembourg. Première partie. Plantes phanérogames. Imprimerie V. Buck, Luxembourg. 279 S.
• Koltz, J.-P.-J., 1875. Dendrologie luxembourgeoise. Catalogue des arbres, arbrissaux et arbustes spontanés, subspontanés ou introduits dans les cultures du Grand-Duché de  Luxembourg. Imprimerie de V. Buck, Luxembourg.
• 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-. Robinia pseudoacacia 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. Robinia pseudoacacia 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 2019-09-06]
• Pfeiffenschneider, M., P. Gräser & C. Ries, 2014a. Distribution of selected neophytes along the main rivers of Luxembourg. Bull. Soc. Nat. luxemb. 115: 101-108. [PDF 3668 KB]
• Pfeiffenschneider, M., P. Gräser & C. Ries, 2014b. Distribution of selected neophytes along the national railway network of Luxembourg. Bull. Soc. Nat. luxemb. 115: 95-100. [PDF 1457 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]
• Schneider, N. & T. Walisch, 2009. Sur la présence au Luxembourg d’Obolodiplosis robiniae (Haldeman, 1847) (Insecta, Diptera, Cecidomyiidae). Bull. Soc. Nat. luxemb. 110: 161-166.
• 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.
• 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, 111 p. [pdf 9,9 MB]
• Wikipedia Luxembourg, 2013. Kaaschtel. URL: http://lb.wikipedia.org/wiki/Kaaschtel [2013-09-27].

 Page content last updated on 2021-08-04. Last proofread by Caroline Grounds on 2019-11-21.

1. Baraton 2021: 353. CABI 2019 mentions 1604.[↩]
2. ”Il paraît que les premiers peupliers d’Italie plantés dans le Grand-Duché, l’ont été sur le domaine de Berg vers 1669, où ils avaient été apportés d’Italie par Jean-Mathias de Blochausen. Ce dernier les a importés lors d’un voyage qu’il a fait en Italie, et à l’occasion duquel il a aussi introduit les premiers acacias dans le pays.”[↩]
3. Original text: “Il est fréquemment et avantageusement cultivé sur nos talus, les marnes irisées pauvres, dans les bosquets, les promeandes, et il sert même quelquefois à faire des haies de clôture. Les premiers sujets de robinier plantés dans le Grand-Duché ont été importés d’Italie vers 1669 par un de Blochausen. Pendant plus d’un siècle cet arbre était encore rare dans le pays, attendu que M. de la Fontaine, ancien gouverneur du Grand-Duché, a cité comme l’un des premiers sujets de cet arbre chez nous, un acacia planté en 1787 par M. le baron de Maréchal dans le jardin dépendant du château de Stadtbredimus.” (Fischer 1872: 37-38).[↩]
4. Original text: “Le bois d’acacia sert à divers usages: il est recherché pour pièce de résistance, manches d’outils etc. Ses feuilles donnent un excellent fourrage et ses fleurs sont butinées par les abeilles” (Krombach 1875: 115).[↩]
5. Address: Centre national de littérature, 2, rue Emmanuel-Servais, L-7565 Mersch. http://www.cnl.public.lu [↩]

	Giant knotweed, Sakhalin knotweed	Status LU: established. 1st record: LU & ITW 1959.
	Sachalin-Knuetkraut	Status Eur.: established. 1st record: UK 1860s. IAS of EU concern (2025).
	Renouée de Sakhaline	RA: ISEIA: B1 – Watch List. Harmonia+: 0,59.
	Sachalin-Staudenknöterich, Riesen-Knöterich	Wikipedia: | Wikispecies: | CABI
	Sachalinse duizendknoop	Back to the list of neophytes

Brief description

Giant knotweed bordering the Alzette river in Luxembourg City.

Like other Asiatic knotweeds, Reynoutria sachalinensis (F. Schmidt) Nakai 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. Giant knotweed produces a small number of viable seeds, but seedlings are seldom observed in the wild. 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.

Reynoutria sachalinensis is able to monopolise space and to form dense and persistent populations. It can outcompete most of native herbaceous plant species thanks to early seasonal development, high growth rate and productivity, abundant leaf cover, allelochemical production and clonal spread associated with an extraordinarily high rate of proliferation of below-ground organs. It can even outcompete Reynoutria japonica on alluvial riverbanks. Its development reduces plant and invertebrate species diversity, alters habitats for fish and wildlife, change light and energy conditions of the ecosystem, and favours river bank erosion during the winter. It can also break through tarmac and thin layers of concrete, and can penetrate some flood defences (Branquart et al. 2011).

Status and distribution in Luxembourg

Reynoutria sachalinensis (F. Schmidt) Nakai was first documented on 14th May 1959 in Lëtschet (Municipality of Steinsel) by Léopold Reichling (1921-2009) (MNHNL 2000-).

Giant knotweed is less common and less widespread in Luxembourg than its relatives Bohemian knotweed (Reynoutria × bohemica), and Japanese knotweed (Reynoutria japonica). It sometimes builds huge colonies along riparian ecosystems, as can be seen along the river Alzette in Luxembourg City (beside the Neumünster Abbey in the Grund district) and along the Sûre east of Diekirch. It is mostly found as an ornamental plant in private gardens. Populations in the wild are often the result of people fly-tipping their knotweed clippings.

Risk assessment

ISEIA protocol

B1 (2+2+3+3) = Watch List (Ries et al. 2013: 18).

Harmonia+ protocol

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

Worldwide distribution

Bibliography

• Albers, M., S. Kohn, J. Steng & M. Pfeiffenschneider, 2001. – Problematik der Bioinvasion. Kartierung von Japan-Knöterich, Riesenbärenklau und Indischem Springkraut an Woltz, Clerve und Wiltz. Ergebnisse der Kartierung. – Studie des Büros ERSA im Auftrag von: Administration des eaux & forêts, arrondissement nord. August 2001. 7S. + Anhang.
• 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]
• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum, F. Verloove & A. Vervoort, 2011. Harmonia database: Fallopia sachalinensis (F. Schmidt Petrop.) Ronse Decr. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-11]
• CABI, 2019. Fallopia sachalinensis. 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)
• 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-. Fallopia sachalinensis (F. Schmidt Petrop.) Ronse Decr. 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. Fallopia sachalinensis (F. Schmidt Petrop.) Ronse Decr. 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]
• Pfeiffenschneider, M., 2001. – Problematik der Bioinvasion. Nationales Inventar von Riesenbärenklau, Indischem Springkraut und exotischen Knötericharten. Ergebnisse einer Umfrage und Konzept zur Bekämpfung der Riesenbärenklaubestände. – Studie des Büros ERSA im Auftrag von: Administration des eaux & forêts, Service de la conservation de la nature, November 2001. 23 S. + Anhang, Luxembourg.
• 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)
• Pfeiffenschneider, M., 2008. Neophyten in Luxemburg – Projekt Bioinvasion 2007. Arbeitsbericht. 18 S. (pdf)
• Pfeiffenschneider, M. & M. Owaller, 2000. – Kartierung von Japan-Knöterich, Riesenbärenklau und Indischem Springkraut an der Obersauer. Theoretische Grundlagen und Ergebnisse der Kartierung.. – Studie des Büros ERSA im Auftrag von: Administration des eaux & forêts, acrrondissement nord. August 2000. 37S. + Anhang, Luxembourg.
• 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 2025-07-29. Last proofread by Caroline Grounds on 2019-11-18.