Danish scurvygrass	Status LU: established. 1st record: LU & ITW 2011.
	Dänescht Läffelblat	Status Eur.: established.
	Cochléaire du Danemark	RA: ISEIA: C1. Harmonia+: 0,02
	Dänisches Löffelkraut	Wikipedia: | Wikispecies:
	Deens lepelblad	Back to the list of neophytes

Brief description

Cochlearia danica L. is native to coastal habitats in the following countries in Europe: Belgium, Denmark, United Kingdom, France, Finland, Netherlands, Ireland, Germany, Norway, Portugal, Russia, Spain and Sweden (Fekete et al. 2018: 27). This salt-tolerant coastal flowering plant is now flourishing along roads and motorways in Europe, especially under the crash barriers in the central reservation. Its success has been attributed to its ability to survive the effects of salts distributed by gritters in winter and its small seeds being spread by the high speed of cars in the fast lane. Literature data indicate a rapid spread of this species along European roads, of 62–65 km/year (Fekete et al. 2018: 28). Full of vitamin C, the Danish scurvygrass gets its name from sailors chewing it to avoid scurvy. The mauve flowers are 4-5mm in diameter (Wikipedia contributors 2019).

Status and distribution in Luxembourg

Cochlearia danica L. was first collected on 2011-05-05 in Luxembourg-Kirchberg by Jean-Claude Kirpach (MNHNL 2000-).¹ Since this first observation, the species has been spotted twice along the controlled-access A6 highway near Windhof and Aire de Capellen (Krippel et al. 2018: 61-62). The Danish scurvygrass continues to expand eastward along this highway (Krippel et al. 2020).

In a recent survey of salt-tolerant vascular plant species along roads in Luxembourg (Ehl et al. 2019), the Danish scurvygrass was not recorded, although it was expected to be found, as it was recently recorded in Trier in Germany (Hand et al. 2016) and Arlon in Belgium (Remacle 2015).

On 2018-04-11, its presence was confirmed also along the A1 motorway to Germany, more than 100,000 plants especially along the central berm, but also along the lateral strips, over several km with interruptions (Krippel et al. 2020).

In April 2021, further occurrences of the species were discovered, as white flowering patches along the A7 motorway between Mersch and Schieren: Mierscherbierg-Rouscht, after the Colmarbierg slip road and at the Schieren exit (Krippel in litt. 2021).

The general spread of Cochlearia danica has been following the pattern of roads leading from the coast to the hinterland (Brandes 2009). The Danish scurvygrass, quite common on the coasts of Western Europe, is expanding inland mainly in the north and centre of the flora territory, following the massive use of snow removal salts in winter, especially along highways (Lambinon & Verloove 2012: 270-271).

Risk assessment

ISEIA protocol

C1 (1+1+1+1). First assessed 24 January 2019 by Manou Pfeiffenschneider and Christian Ries.

Harmonia+ protocol

Overall risk score 0,02 = (Overall Invasion score 0,42 x Overall Impact score 0,07) (Ries et al. 2020).

Worldwide distribution

Bibliography

• Brandes, D., 2009. Autobahnen als Wuchsorte und Ausbreitungswege von Ruderal- und Adventivpflanzen. Braunschweiger Naturkundliche Schriften 8(2): 373-394.
• Ehl, S., K. Mildenberger, T. Frankenberg & C. Ries, 2019. Halophytes in roadside habitats: a survey of salt-tolerant vascular plant species along roads in Luxembourg. Bulletin de la Société des naturalistes luxembourgeois 121: 37-51. [PDF 24.03 MB]
• Fekete, R., A. Mesterházy, O. Valkó & V. A. Molnár, 2018. A hitchhiker from the beach: the spread of the maritime halophyte Cochlearia danica along salted continental roads. Preslia 90: 23–37. DOI: 10.23855/preslia.2018.023
• GBIF 2020. Cochlearia danica L. in GBIF Secretariat (2019). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2020-02-28.
• Hand, R., H. Reichert, W. Bujnoch, U. Kottke & S. Caspari, 2016. Flora der Region Trier (1. & 2. Band). Verlag Michael Weyand GmbH, Trier, 1637 pp.
• 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-. Cochlearia danica 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. Cochlearia danica 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]
• Remacle, A., 2015. L’intérêt botanique des espaces verts autoroutiers : le cas de l’autoroute E411 près d’Arlon (province de Luxembourg, Belgique). Dumortiera 107: 3-21.
• 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]
• Wikipedia contributors, 2019. Cochlearia danica L. in Wikipedia, The Free Encyclopedia, 16 September 2019. URL: https://en.wikipedia.org/w/index.php?title=Cochlearia_danica&oldid=916018993 [accessed 3 October 2019]

Not cited bibliography concerning our neighbouring areas

• Cochard, P.-O., 2005. Cochlearia danica L., une halophyte adventice des autoroutes. Symbioses nouvelle série 13 : 69-74. [http://pierreo.cochard.free.fr/cv_poc/Cochard_Cochlearia.pdf]
• Havrenne, A., 1995. Cochlearia danica, plante halophile nouvelle pour le Hainaut. Natura Mosana 48 : 68-69.
• Mennema, J., 1986. Cochlearia danica L. op weg naar de binnenlanden van België en West-Duitsland. Dumortiera 34-35 : 139-142.
• Olivier, J.-F., 1996. Nouvelles stations de Cochlearia danica L. près de Bruxelles. Dumortiera 66 : 1-3.
• Remacle, A., 2015. L’intérêt botanique des espaces verts autoroutiers : le cas de l’autoroute E411 près d’Arlon (province de Luxembourg, Belgique). Dumortiera 107 : 3-21.
• Robyns, J., 1978. Floristische mededelingen : Cochlearia danica te Ezemaal. Dumortiera 10 : 296.
• Zwaenepoel, A., 1994. Cochlearia danica L. als bermhalofyt langs verkeerswegen in het Vlaamse binnenland. Dumortiera 55-57 : 43-49.

 Page content last updated on 2021-06-18. Last proofread by Caroline Grounds on 2019-11-12.

1. The specimen was determined by Thierry Helminger, MNHNL.[↩]

	Balfour’s touch-me-not, Kashmir balsam	Status LU: casual. 1st record: LU <1995, ITW 2016.
	Balfour-Sprangkraut	Status Eur.: established. 1st record: FR ~1890.1
	Impatiente, balsamine de Balfour	RA: ISEIA: B1 – Watch List. Harmonia+: 0,09.
	Balfour’s Springkraut	Wikipedia: | Wikispecies: | CABI
	Tweekleurig springzaad	Back to the list of neophytes

Brief description

Impatiens balfourii Hook.f. is a species of the genus Impatiens known by the common names Balfour’s touch-me-not, Kashmir balsam, and Poor Man’s Orchid. It belongs to the family Balsaminaceae. It is native to the Himalayas, particularly Kashmir and surrounding areas, where it grows on mountains of 5,000 to 6,000 feet. It was brought back to England and many other European countries as a garden plant. It can now be found growing wild as a garden escapee in Europe. In the wild the plant occurs along the banks of rivers, on roadsides, and in wastelands. It thrives in cool and moist areas, at an altitude of 100–600 m above sea level (Wikipedia contributors 2019).

Status and distribution in Luxembourg

In Luxembourg, Impatiens balfourii Hook.f. was first observed in 2009 in the Mediterranian Garden in Schwebsange, when “Natur & Ëmwelt Fondatioun Hëllef fir d’Natur” took over the management of the premises. The former owners recalled having brought the species from a trip to Lago Maggiore in Northern Italy in the late 1980ies or early 1990ies (Moes 2021). We thus assume the 1st record of the species is to be dated before 1995.

The species was first observed in the wild by Roland Proess on 2016-08-05 at Schëttermarjal on the edge of the Kirchberg plateau in Luxembourg City (Krippel & Proess 2017). The species is at present considered to be subspontaneous; it may however have the potential of becoming naturalised in Luxembourg due to climate change (Krippel & Proess 2017).

A second observation of this melliferous Himalayan species was made on 2020-08-28 on a ruderal stand next to a stone wall in Neudorf (MNHNL, iNaturalist & GBIF 2021).

Cultivated as an ornamental garden plant. Found subspontaneously here and there, or sometimes naturalised locally, especially in the south (Lambinon & Verloove 2012: 480).

Impatiens balfourii has its origins in the west Himalayan region (Grey-Wilson 1983). This species of the Balsaminaceae family was simultaneously introduced in 1901 at the Jardin des plantes de Montpellier and the Botanical Garden of Edinburgh (Adamowski 2009). It has been cultivated in Europe as an ornamental plant since the beginning of the 20^th century; in Luxembourg it is grown, for example, in the Jardin méditerranéen in Schwebsange. Nowadays the species is naturalised in major parts of south and central Europe (Adamowski 2009, Schmitz & Dericks 2010).

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

B1 (3+3+3+1) = Watch List. First assessed 16 February 2017 by Yves Krippel and Christian Ries.

Harmonia+ protocol

Overall risk score 0,09 = (Overall Invasion score 0,17 x Overall Impact score 0,30) (Ries et al. 2020).

Worldwide distribution

Bibliography

• Adamowski, W., 2009. Impatiens balfourii as an emerging invader in Europe. Neobiota 8: 183-194.
• CABI, 2019. Impatiens balfourii. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-03-02]
• GBIF, 2020. Impatiens balfourii Hook.f. in GBIF Secretariat (2019). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei [accessed 2020-03-02]
• Grey-Wilson, C., 1983. A survey of the genus Impatiens in cultivation. The Plantsman 5(2): 86-102.
• Krippel, Y. & R. Proess, 2017. Impatiens balfourii Hook.f. (Balsaminaceae), nouvelle espèce subspontanée au Luxembourg ?! Bull. Soc. Nat. luxemb. 119: 55-61 [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.
• Matthews, J., R. Beringen, E. Boer, H. Duistermaat, B. Odé, J. L. C. H. van Valkenburg, G. van der Velde & R. S. E. W. Leuven, 2015. Risks and management of non-native Impatiens species in the Netherlands. Ed. by Radboud University, FLORON and Naturalis Biodiversity Center, Reports Environmental Science 491, 2015. 177 S. [PDF]
• MNHNL, 2000-. Impatiens balfourii Hook.f. 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, 2021. Impatiens balfourii Hook.f. 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 2021-01-12]
• Moes, G., 2021. Personal communication by E-mail to Yves Krippel on 2021-01-09.
• 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]
• Schmitz, U. & G. Dericks, 2010. Spread of alien invasive Impatiens balfourii in Europe and its temperature, light and soil moisture demands. Flora 205: 772-776.
• 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.
• Wikipedia contributors, 2019. Impatiens balfourii Hook.f. in Wikipedia, The Free Encyclopedia, 22 September 2019, 14:49 UTC, <https://en.wikipedia.org/w/index.php?title=Impatiens_balfourii&oldid=917160050> [accessed 2019-10-11]

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

1. Cf. Matthews et al. 2015: 46.[↩]

	n/a	Status LU: established. 1st record: LU & ITW 2007.
	Verschiddesomeg Méil	Status Eur.: established. 1st record: FR 1906.
	Arroche hétérosperme	RA: ISEIA: C2. Harmonia+: 0,09
	Verschiedensamige Melde	Wikipedia: | Wikispecies: | CABI
	Grijze melde	Back to the list of neophytes

Brief description

In its native Central Asia, Atriplex micrantha Ledeb. grows in steppes on saline soil, on the shores of water, or in the steppe and semi-desert zone. The species was introduced into large parts of Europe through trade and traffic. It was probably unintentionally introduced to Central Europe from Russia with grain supplies. Its first finds date from 1906 in Alsace (Rhine port). From there, it has spread out strongly along the waterways and traffic routes in recent decades (Wikipedia contributors 2019).

Status and distribution in Luxembourg

The annual halophyte Atriplex micrantha Ledeb. (syn.: A. heterosperma Bunge), once known as a very rare weed, began to naturalize in the flora territory in 2003. It spread rapidly along motorways, entering this territory apparently from the east and southwest (Germany and French Lorraine) (Lambinon & Verloove 2012: 168).

The species was first spotted in Hellange (Municipality of Frisange) on 14 October 2007, in a roundabout at a construction site on controlled-access highway E29 (Weicherding 2007, MNHNL 2000-, herbarium nr 22483).¹

Since this single observation, the species managed to invade the Luxembourg highway network unnoticed, until a large population was spotted in summer 2015 in Potaschberg on the A1 highway between Trier and Luxembourg (Krippel & Colling 2016: 30).²

A field inspection in autumn 2015 revealed the invasive plant grows in the median strip of the A1 almost from the German border until Luxembourg city in huge very dense populations³, which confirms the Belgian point of view that “the species is still insufficiently known and widely neglected”.⁴ Atriplex micrantha, which was dominant in the middle part of the median strip, occurred together with the following species: Senecio inaequidens (dominant on the borders of the median strip), Mercurialis annua, Plantago intermedia, Prunus spinosa and Rosa rugosa.

On 13 October 2015 the species was spotted along the Jersey barrier of highway A6 between the Belgian border and Mamer⁵.

Since then the species managed to travel north along the A7 highway until Colmar-Berg and the B7 national highway until Ettelbruck (Krippel et al. 2018: 60). Since then, the expansion of the species is ongoing along these highways (Krippel et. al 2020: 33).

Atriplex micrantha is very salt-tolerant and benefits from the extensive use of de-icing salt along motorways during winter. It probably arrived in Luxembourg via its large secondary distribution area in Germany, namely the A1 from Trier. It is present in our neighbouring regions in Belgium (Verloove 2006), Lorraine (Georges 2006) and Saarland (Weicherding 2007).

Risk assessment

ISEIA protocol

C2 (3+1+1+1). First assessed 16 February 2017 by Yves Krippel and Christian Ries.

Harmonia+ protocol

Overall risk score 0,09 = (Overall Invasion score 0,36 x Overall Impact score 0,25) (Ries et al. 2020).

Worldwide distribution

Bibliography

• Georges, N., 2006. Note sur deux nouvelles espèces de Chenopodiaceae adventices en Lorraine : Bassia scoparia (L.) Voss et Atriplex micrantha Ledeb. Willemetia 48: 1-4. [PDF]
• Krippel, Y. & G. Colling, 2016. Notes floristiques. Observations faites au Luxembourg (2014-2015). Bull. Soc. Nat. luxemb. 118 : 27-51.
• 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-. Atriplex micrantha Ledeb. 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 2019-10-02]
• MNHNL, iNaturalist & GBIF, 2019. Atriplex micrantha Ledeb. 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 2019-10-02]
• 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]
• Verloove, F., 2006. Atriplex micrantha, een nieuwe neofyt langs belangrijke verkeerswegen in België. Dumortiera 88: 15-20.
• Weicherding, F.-J., 2007. Zur Verbreitung und Soziologie der adventiven Melden Atriplex micrantha Ledeb. (Verschiedensamige Melde), Atriplex sagittata Borkh. (Glanz-Melde) und Atriplex oblongifolia Waldst. et Kit. (Langblättrige Melde) (Chenopodiaceae) im Saarland und in angrenzenden Gebieten. Abh. Delattinia 33: 117-139.
• Wikipedia contributors, 2019. Seite „Verschiedensamige Melde“ in Wikipedia, Die freie Enzyklopädie. Bearbeitungsstand: 1. Mai 2019, 23:11 UTC. URL: https://de.wikipedia.org/w/index.php?title=Verschiedensamige_Melde&oldid=188124273 [accessed 23 October 2019]

 Page content last updated on 2021-06-02. Last proofread by Caroline Grounds on 2019-11-13.

1. Atriplex micrantha was first spotted in Luxembourg on 14 October 2007 by German Horticulturist Franz-Josef Weicherding, St. Ingbert/Saar. He offered a specimen to the herbarium of the MNHNL (Acc Nr. MNHNL 2011/47).[↩]
2. Atriplex micrantha was spotted on 15 August 2015 by botanist Yves Krippel, scientific cooperator of the National Museum of Natural History.[↩]
3. Inspection was carried out on 8 October 2015 by Dr Christian Ries and Dr Jim Meisch, curators at the National Museum of Natural History (WGS 84 6.41204, 49.68373). This “field trip” on the middle strip of a highway had to be coordinated with the highways unit of the department of civil engineering.[↩]
4. Cf. Atriplex micrantha in the Manual of the Alien Plants of Belgium[↩]
5. The plants were smaller (± 40-50 cm) than on the A1 (± 150 cm). Observation by Dr Christian Ries while driving car in the mentioned direction.[↩]

	Billard’s bridewort	Status LU: established. 1st record: LU <1875, ITW 1949.
	Billard-Kluddertrausch	Status Eur.: established. 1st record: ?
	Spirée de billard	RA: ISEIA: B1, Watch List. Harmonia+: 0,00.
	Billards Spierstrauch	Wikipedia: | Wikispecies:
	Billardspirea	Back to the list of neophytes

Brief description

Spiraea ×billardii Hérincq is a sterile horticultural hybrid between Spiraea alba Du Roi and Spiraea douglasii Hook. It only reproduces clonally. It grows mainly in ruderal areas and in riparian habitats. Plant habitat preferences are poorly known so far.

S. billardii is a fast-growing rhizomatous species, propagating clonally. As for other Spiraea species, it may easily form dense monospecific thickets smothering native vegetation. It is not known, however, if it has the capacity to inhibit plant successions like S. alba (Branquart et al. 2010).

Status and distribution in Luxembourg

Spiraea ×billardii Hérincq was first mentioned for Luxembourg by Koltz (1875: 66) in the section about S. salicifolia. We thus consider the first record to be anterior to 1875 (Ries & Krippel 2021).

François Léon Lefort (1917-1975) first documented the species in the wild on 1949-08-03 “along the Ernz Blanche downstream of Medernach, 300 m from the road to Diekirch”  (Herb. LUX specimen № 21985; MNHNL 2000-).

Currently, 5 records of Billard’s bridewort are accessible through the MNHNL-mdata portal (MNHNL, iNaturalist & GBIF 2019).

This horticultural species is often grown for ornamental purposes in parks and gardens. Subspontaneous or naturalised: old hedges, roadsides, embankments, wastelands (Lambinon & Verloove 2012: 326).

This Spiraea is by far the most widespread in the wild. However, the identity of the plant remains debatable: some authors distinguish Spiraea ×billardii (very pale pink corolla; narrowly conical inflorescence) and Spiraea ×Silverside Silverside (Spiraea douglasii × salicifolia) (bright pink corolla; subcylindrical inflorescence; leaf blade more regularly toothed, almost to the base), which would be much more common. However, the recognition of these two taxa seems difficult and therefore S. billardii is sometimes treated in a broad sense as a hybridogenic species that is more or less variable (Lambinon & Verloove 2012: 326).

Risk assessment

ISEIA protocol

B1 (2+2+3+2) = Watch List, reassessed on 24 January 2019 by C. Ries and M. Pfeiffenschneider. Original assessment: B0 (2+2+3+2) = Alert List (Ries et al. 2013: 19).

Harmonia+ protocol

Overall risk score 0,00 = (Overall Invasion score 0,00 x Overall Impact score 0,43) (Ries et al. 2020).

Overall risk score 0,00 = (Overall Invasion score 0,00 x Overall Impact score 0,43) (Ries et al. 2020).

Worldwide distribution

No worldwide distribution map available at CABI or GBIF (2020-03-04).

Bibliography

• Branquart, E., P. Dupriez, S. Vanderhoeven, W. Van Landuyt, F. Van Rossum & F. Verloove, 2010. Harmonia database: Spiraea ×billardii Hérincq. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-15]
• 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-. Recorder-Lux, database on the natural heritage of the Grand Duchy of Luxembourg. National Museum of Natural History, Luxembourg. Spiraea ×billardii Hérincq observed on 1949-08-03, occurrence ID DSS00439000013HF, via https://mdata.mnhn.lu [accessed 2021-03-12].
• MNHNL, iNaturalist & GBIF, 2019. Spiraea ×billardii Hérincq 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. 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 2021-03-12. Last proofread by Caroline Grounds on 2019-11-21.

	Tall goldenrod	Status LU: established. 1st record: LU & ITW 1882.
	Riseg Goldrutt	Status Eur.: established. 1st record: ~1750.1
	Verge d’or géante	RA: ISEIA: A2, Black List. Harmonia+: 0,26.
	Riesen-Goldrute	Wikipedia: | Wikispecies: | CABI
	Late guldenroede	Back to the list of neophytes

Brief description

Solidago gigantea Ait. can grow in a wide range of soil conditions but is not shade-tolerant. The plant is found in many disturbed and nitrogen-rich sites such as ruderal areas, fallow lands, abandoned fields, river banks, etc. and also colonises humid grasslands. It can build up dense and long-lasting populations and easily outcompete native plants, including tree seedlings. Competitive ability is favoured by allelopathic interactions. Once established, the plant may remain dominant for a long period of time and often prevents natural colonisation by woody species (Branquart et al. 2010).

Status and distribution in Luxembourg

The oldest herbarium specimen at the MNHNL was collected in 1882 by Jean Feltgen (1833-1904) in a hedge near the village of Angelsberg (Specimen № 15568, MNHNL 2000-). This specimen was labeled Solidago canadensis L. and later verified as Solidago gigantea var. serotina (O. Kunze) Cronq.

The next oldest herbarium specimen at the MNHNL was collected under its synonym Solidago serotina Ait. on 1887-09-08 by Jean Feltgen (1833-1904) in a garden (“jardin Bosseler”) in Mersch (Specimen № 15601, MNHNL 2000-). The next record is a herbarium specimen collected by Jos Witry on 15 July 1937 in gardens in Rumelange (Specimen № 50850, MNHNL 2000-).

Léopold Reichling (1921-2009) reported the species on 1960-09-22 in several locations of the Grund district in Luxembourg City (Bock, Stierchen, Breedewee) (MNHNL 2000-).

Currently, 78 records of tall goldenrod are accessible through the MNHNL-mdata portal (MNHNL, iNaturalist & GBIF 2019).

This melliferous species native to North America is naturalised in Europe: fairly common to fairly rare, present in waterfronts, forest edges, wastelands, wastelands; often in large stands (Lambinon & Verloove 2012: 703).

This species includes populations in North America with variable chromosome numbers. Naturalised plants in Europe have generally been reported to Solidago gigantea subsp. serotina (O. Kuntze) McNeill, still known to be tetraploid. The question remains, however, whether Solidago gigantea subsp. gigantea, diploid, also exists in Europe, and especially whether the two taxa are morphologically identifiable. The problem remains to be studied in the wild (Lambinon & Verloove 2012: 703).

Risk assessment

ISEIA protocol

A2 (3+2+3+3) = Black List (Ries et al. 2013: 19).

Harmonia+ protocol

Overall risk score 0,20 = (Overall Invasion score 0,63 x Overall Impact score 0,42) (Ries et al. 2020).

Worldwide distribution

Bibliography

• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum & F. Verloove, 2010. Harmonia database: Solidago gigantea Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-15]
• CABI, 2019. Solidago gigantea. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-03-04]
• 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-. Solidago gigantea Aiton 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. Solidago gigantea Aiton 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. 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 2021-09-06. Last proofread by Caroline Grounds on 2019-11-21.

1. Cf. CABI 2019.[↩]

	Canada goldenrod	Status LU: established. 1st record: LU & ITW <1872.
	Kanadesch Goldrutt	Status Eur.: established. 1st record: 1645.1
	Verge d’or du Canada	RA: ISEIA: A2, Black List. Harmonia+: 0,39.
	Kanadische Goldrute	Wikipedia: | Wikispecies: | CABI
	Canadese guldenroede	Back to the list of neophytes

Brief description

In its native range, the Canada goldenrod is found mainly on forest edges and roadsides, in abandoned fields and other unmanaged areas which it colonises rapidly after abandonment. Where it has been introduced, it occupies the same habitats as in its native range but also occurs in dry meadows of high conservation value and on wetland fringes. S. canadensis is a pioneer and light-demanding species that occurs over a wide range of soil fertility and texture conditions. It can eliminate almost all other plant species; competitive ability is favoured by allelopathic interactions. Once established, the plant may remain dominant for a long period of time and often prevents natural colonisation by woody species (Branquart et al. 2011).

Status and distribution in Luxembourg

The oldest reference to the species dates from 1872 and states that the species is cultivated for garden decoration, and that it often becomes naturalised in the vicinity of homes and on cemeteries (Fischer 1872: 82). Koltz (1873: 128) lists the species as “cultivated and sometimes subspontaneous near homes and waterways”. Koltz (1874: 30) states that it also becomes naturalised in the vicinity of watercourses. Krombach (1875: 343) states that the species is cultivated and occurs subspontaneously very rarely (RR) in the vicinity of houses. According to Lambinon & Verloove (2012: 703), this naturalised and melliferous species can be found quite rarely (AR-R) in waterfront, forest edges, vacant lots and wastelands.

The first scientific record for Luxembourg that we know of was made by François Léon Lefort (1917-1975) on 17th August 1949 in the Clausen district of Luxembourg City, in neglected gardens and beside paths at the site of the former Mansfeld park (Specimen № 26916, MNHNL 2000-). 174 observations are accessible via the MNHNL-mdata portal (MNHNL, iNaturalist & GBIF 2019).

Risk assessment

ISEIA protocol

A2 (3+2+3+3) = Black List (Ries et al. 2013: 19).

Harmonia+ protocol

Overall risk score 0,39 = (Overall Invasion score 0,71 x Overall Impact score 0,55) (Ries et al. 2020).

Worldwide distribution

Bibliography

• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum, F. Verloove, 2011. Harmonia database: Solidago canadensis L. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-03]
• CABI, 2014. Solidago canadensis. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-03-04]
• 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.
• MNHNL, 2000-. Solidago canadensis 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 2019-09-06]
• MNHNL, iNaturalist & GBIF, 2019. Solidago canadensis 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]

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

1. Cf. CABI 2019.[↩]