Solidago canadensis

Solidago canadensis L. (N-Am.) – A rather rare and probably decreasing, naturalised escape from cultivation or garden throw-out. First reliably recorded in 1863 on the margins of a lake in Virelles. Solidago canadensis is most often found by railway tracks, road verges, on urban wasteland, dumps, etc. It favours slightly humid, nitrophilous substrates. Solidago canadensis is possibly less invasive than S. gigantea in Belgium. It more rarely occurs in massive stands and is more frequently confined to man-made, often urban habitats (see also Ottich 2005). It probably only reproduces clonally. Additional information on the invasion history of Solidago canadensis in Belgium is available at:

Solidago canadensis was long thought to be the only American representative of the genus in Belgium (see also Lawalrée & Vanden Berghen 1946). However, most records turned out to be erroneous and, in fact, belonged with Solidago gigantea. At present it is much rarer than the latter; it is unclear whether it has always been rarer or simply has decreased in the past decades.

Solidago canadensis is a fairly variable species (see Semple & al. 1999, Semple & Cook 2006) and its specific boundaries long remained unclear. At present, the segregation of Solidago altissima L. (syn.: S. canadensis subsp. altissima (L.) Bolos et Vigo, S. canadensis var. scabra (Muhl.) Torr. et A. Gray) has become widely accepted. Weber (1997a, 2000) sursprisingly ascribed all European populations of Solidago canadensis to this species (contrary to all previous reports; see for instance McNeill 1976). Solidago altissima was rather poorly circumscribed in Europe so far. It was usually said to have stems that are hairy throughout, slightly larger capitulae and longer ligular florets. According to Stace (2010) it also has more sharply serrate leaves. At least this feature does no longer hold true: according to Semple & Cook (2006) Solidago altissima (at least the widespread var. altissima) is distinguished by mid cauline leaves that are minutely serrate to entire. As a matter of fact, a large majority of the Belgian collections is very uniform and obviously belongs with Solidago canadensis var. canadensis: stems only pubescent in the upper ½ (alas, this feature is rarely visible in herbarium collections, the lower parts of a plant rarely being collected), leaves evidently serrate, small capitulae with short ligular florets, etc. Aberrant populations are seldom seen (or under-recorded?), for instance on a railway yard in Virton (St.-Mard) in 2008: stems more or less (sparsely) hairy to the base, capitulae slightly larger and ligular florets slightly longer. Such plants have been recorded elsewhere in Europe as well and have been ascribed to Solidago anthropogena nom. prov. (Scholz 1993). It is believed to be a weedy cultigen, probably of European origin. The genuine occurrence of Solidago altissima var. altissima in Belgium was recently confirmed (Verloove & al. 2017). According to Semple & Cook (2006) it is introduced worldwide and the most common and weedy member of the group. A closer examination and better sampling of Solidago canadensis-like plants is recommended.

A hybrid with native Solidago virgaurea has been repeatedly reported from Europe (Solidago ×niederederi Khek; e.g. Burton 1980, Pliszko 2015, Karpavičienė B. & Radušienė 2016). Only recently the hybrid of origin of such plants has been confirmed using molecular techniques (Pliszko & Zalewska Gałosz).

Herbarium specimen

Solidago canadensis, Brussel (Haren), roadside in industrial area, August 2011, F. Verloove  Solidago canadensis [in background also S. gigantea], Flobecq (La Houppe), former sand pit, August 2009, F. Verloove

Selected literature:

Adolphi K. (1995) Neophytische Kultur- und Anbaupflanzen als Kulturflüchtlinge des Rheinlandes. Nardus 2: 272 p.

Blackwell W.H. & Powell M.J. (1981) Observations on late season pollination of Solidago canadensis L. (Asteraceae) in southwest Ohio. Castanea 46(2): 136-139.

Burton R. (1980) Solidago x niederederi Khek in Britain. Watsonia 13(2): 123-124.

Cornelius R. (1990a) The strategies of Solidago canadensis L. in relation to urban habitats. 1. Resource requirements. Acta Oecol. 11: 19-34.

Cornelius R. (1990b) The strategies of Solidago canadensis L. in relation to urban habitats. 3. Conformity to habitat dynamics. Acta Oecol. 11: 301-310.

Cornelius R. & Faensen-Thiebes A. (1990) The strategies of Solidago canadensis L. in relation to urban habitats. 2. Competitive ability. Acta Oecol. 11: 145-154.

Croat T. (1972) Solidago canadensis complex of the Great Plains. Brittonia 24(3): 317-326.

Dong M., Lu J.-Z., Zhang W.-J., Chen J.-K. & Li B. (2006) Canada goldenrod (Solidago canadensis): An invasive alien weed rapidly spreading in China. Acta Phytotaxonomica Sinica 44(1): 72-85.

Druet J. & Duvigneaud J. (1951) Note sur quelques phanérogames adventices. Lejeunia 15: 59-62.

Guzikowa M. & Maycock P.F. (1986) The invasion and expansion of three North American species of goldenrod (Solidago canadensis L. sensu lato, S. gigantea Ait. and S. graminifolia (L.) Salisb.) in Poland. Acta Soc. Bot. Pol. 55(3): 367-384.

Karpavičienė B. & Radušienė J. (2016) Morphological and Anatomical Characterization of Solidago × niederederi and Other Sympatric Solidago Species. Weed Science 64(1): 61-70. [available online at:]

Lawalrée A. & Vanden Berghen C. (1946) Note sur quelques phanérogames de la flore belge. Bull. Soc. Roy. Bot. Belg. 78: 100-105.

McNeill J. (1976) Solidago. In: Tutin T.G. & al. (eds.), Flora Europaea, vol. 4. Cambridge University Press, Cambridge: 110-111.

Melville M.R. & Morton J.K. (1982) A biosystematic study of the Solidago canadensis (Compositae) complex. 1. The Ontario populations. Canad. J. Bot. 60: 976-997.

Nesom G.L. (1989) The Solidago canadensis (Asteraceae : Astereae) complex in Texas with a new species from Texas and Mexico. Phytologia 67(6): 441-450.

Ottich I. (2005) Solidago canadensis und Solidago gigantea in Frankfurt am Main. Botanik und Naturschutz in Hessen 18: 55-66.

Pliszko A. (2015) Neotypification of Solidago × niederederi (Asteraceae). Phytotaxa 230(3): 297-298. [available online at:

Pliszko A. & Zalewska Gałosz J. (2016) Molecular evidence for hybridization between invasive Solidago canadensis and native S. virgaurea. Biol. Invasions DOI 10.1007/s10530-016-1213-3

Pors B. & Werner P.A. (1989) Individual flowering time in a goldenrod (Solidago canadensis): field experiment shows genotype to be more important than environment. Amer. J. Bot. 76: 1681-1688.

Rebele F. (1989) Der Bleigehalt von Goldrutenblättern (Solidago canadensis L.) in der Umgebung der Akkumulatorenfabrik Sonnenschein in Berlin-Mariendorf. Verhandlungen der Gesellschaft für Ökologie 18: 437-442.

Schmidt W. (1981) Über das Konkurrenzverhalten von Solidago canadensis und Urtica dioica. Verhandlungen der Gesellschaft für Ökologie 9: 173-188.

Scholz H. (1993) Eine unbeschriebene anthropogene Goldrute (Solidago) aus Mitteleuropa. Flor. Rundbr. 27(1): 7-12.

Schuler K. (1982) Blütenbesuch durch Insekten an Solidago canadensis und S. virgaurea eine vergleichende Studie. Ber. Naturwiss.-Med. Vereins Innsbruck 69: 127-144.

Semple J.C. & Cook R.E. (2006) Solidago. In: Flora of North America Editorial Committee (eds.), Flora of North America, vol. 20. Oxford University Press, New York-Oxford: 107-166.

Semple J.C., Faheemuddin H., Chong Y.A., Sorour M.K., Hood J.A., Khamis I., Ma Y. & Kornobis K. (2013) A multivariate morphometric study of the Solidago canadensis / S. lepida complex of Solidago subsect. Triplinerviae. I. Northeastern taxa (Asteraceae: Astereae). Phytoneuron 2013-58: 1-20. [available online at:]

Semple J.C., Rahman H., Sbovski S., Sorour M.K., Kornobis K., Lopez Laphitz R. & Tong L. (2015) A multivariate morphometric study of the Solidago altissima complex and S. canadensis (Asteraceae: Astereae). Phytoneuron 2015-10: 1-31. [available online at:

Semple J.C., Ringius G.S. & Zhang J.J. (1999) The Goldenrods of Ontario: Solidago L. and Euthamia Nutt. (3rd ed.). Univ. Waterloo Biol. Ser. 39: VI + 90 p.

Stace C. (2010) New flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.

Verloove F. (2002) Ingeburgerde plantensoorten in Vlaanderen. Mededeling van het Instituut voor Natuurbehoud n° 20: 227 p.

Verloove F. (2006a) Solidago canadensis. In: Van Landuyt W., Hoste I., Vanhecke L., Van den Bremt P., Vercruysse W. & De Beer D., Atlas van de flora van Vlaanderen en het Brussels gewest. Instituut voor Natuur- en Bosonderzoek, Nationale Plantentuin van België en Flo.Wer: 840.

Verloove F., Zonneveld B.J.M. & Semple J.C. (2017) First evidence for the presence of invasive Solidago altissima (Asteraceae) in Belgium. Willdenowia (in prep.).

Voser-Huber M.L. (1983) Studien an eingebürgerten Arten der Gattung Solidago L. Probleme mit S. gigantea, S. canadensis und S. graminifolia in Naturschutzgebieten des Schweizerischen Mittellandes. Diss. Bot. 68: 1-157.

Walter E. (1987) Zur Verbreitung und zum Verhalten nordamerikanischer Goldruten (Solidago canadensis und S. gigantea) in Oberfranken. Ber. Naturforsch. Ges. Bamberg 62: 27-68.

Weber E. (1997a) Morphological variation of the introduced perennial Solidago canadensis L. sensu lato (Asteraceae) in Europe. Bot. J. Linn. Soc. 123: 197-210.

Weber E. (2000) Biological flora of Central Europe: Solidago altissima L. Flora 195: 123-134.

Werner P.A., Bradbury I.K. & Gross R.S. (1980) The biology of Canadian weeds: 45. Solidago canadensis L. Canad. J. Pl. Sci. 60(4): 1393-1409.

Wittig R. (1978) Zur pflanzensoziologischen und ökologischen Stellung ruderaler Bestände von Solidago canadensis L. und Solidago gigantea Ait. (Asteraceae) innerhalb der Klasse Artemisietea. Decheniana 131: 33-38.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith