Acer saccharinum L. (N Am.) – A rare but increasing escape from cultivation. First reported from the borders of rivers Meuse and Ourthe in 2008 (Verloove 2011). Since then observed as self-seeding in numerous, widely scattered localities. Most records, however, are from the immediate surroundings of planted individuals (often in urban or suburban habitats). The species is also known to reproduce from seed in the Botanic Garden in Meise (Ronse 2011). In addition and more of in importance is the fact that A. saccharinum is increasingly seen in riparian habitats. Records are available, for instance, from rivers Leie/Lys, Maas/Meuse, Ourthe, and Scheldt and from canal banks as well. At present mostly single individuals are involved and genuinely naturalized populations are probably absent. A future naturalization, especially along rivers, is very likely in a near future.
Acer saccharinum was, for quite a long time, thought be unsuccessful as an invader. According to Stace (2010) it rarely sets seed in the British Isles. Aas & al. (2010) found that its seeds were considerably heavier than those of congeneric invasive species such as A. platanoides, A. negundo and A. pseudoplatanus. As a result, it was mostly found in the immediate surroundings of planted individuals, i.e. in parks and urban areas where saplings are readily removed.
In recent years, however, it is naturalizing in riparian habitats in various parts of Europe, for instance in France (Tison & de Foucault 2014), Germany (numerous references), etc.
Selected references
Aas G., Zielinska D. & Lauerer M. (2010) Naturverjüngung von Acer saccharinum auf einer Ruderalfläche in Bayreuth. Ber. Bayer. Bot. Gesell. 80: 161-167. [available online at: https://www.researchgate.net/publication/267244593_Naturverjungung_von_A...
Adolphi K. (1995) – Neophytische Kultur- und Anbau-pflanzen als Kulturflüchtlinge des Rheinlandes. Nardus 2: 272 p.
Adolphi K. (1997) – Neophytische Kultur- und Anbau-pflanzen als Kulturflüchtlinge des Rheinlandes, 1. Nach-trag. Osnabr. Naturwiss. Mitt. 23: 27-36.
Jensen R.J., Ciofani K.M. & Miramontes L.C. (2002) Lines, outlines, and landmarks: morphometric analyses of leaves of Acer rubrum, Acer saccharinum (Aceraceae) and their hybrid. Taxon 51(3): 475-492. [available online at: https://www.researchgate.net/publication/235636436_Lines_Outlines_and_La...
Ronse A. (2011) 'Botanic garden escapes' from the living collections at the Botanic Garden. In: Hoste I. (ed.), The spontaneous flora of the National Botanic Garden of Belgium. Scripta Botanica Belgica 47: 219 p. [available online at: https://www.researchgate.net/publication/289897146_Botanic_garden_escape...
Santamour F.S. & McArdle A.J. (1982) Checklist of cultivated maples: 4. Acer saccharinum L. J.Arboricult. (USA) 8(10): 277-280. [available online at: http://joa.isa-arbor.com/]
Stace C. (2010) New flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.
Tison J.-M. & de Foucault B. (coord.) 2014) Flora Gallica. Flore de France. Editions Biotope, Mèze : xx + 1196 p.
Verloove F. (2011) Fraxinus pennsylvanica, Pterocarya fraxinifolia en andere opmerkelijke uitheemse rivierbegeleiders in België en Noordwest-Frankrijk. Dumortiera 99: 1-10. [available online at: http://www.plantentuinmeise.be/DUMORTIERA/DUM_99/Dum%2099_1-10_Fraxinus%...