Aralia elata (Miq.) Seem. (E-As.) – A rare but recently increasing escape from cultivation. Cited by Verhaeghe (1999) from Brussel and subsequently recorded in, for instance, Antwerpen, Brugge, Hechtel-Eksel (Pijnven), Leuven, Lokeren, Meerhout, Merendree, Neerglabeek, Oostkamp (Waardamme), Roeselare-Beveren, Waasmunster, .... The habitats in which Aralia elata occurs are remarkably diverse. First of all, it has been observed as a relic of cultivation or from clonal growth in park areas. Furthermore, Aralia elata occurs in urban areas: usually single specimens at foot of walls, possibly birdsown. Finally, young specimens of Aralia elata have been observed several times in remote, nature-like habitats, especially in clearings in woods (very likely also introduced by birds). At present, Aralia elata seems to persist very well but is not naturalised yet in Belgium.
The exact origin of the Belgian Aralia elata plants is somewhat unclear. Some are surely associated with discarded garden waste but several are the result of self-sowing. Saplings of Aralia elata are regularly encountered, often in fairly remote places. At least in Japan Aralia elata is dispersed by birds (Sato & Sakai 2004).
The Belgian collections of Aralia elata are slightly heterogeneous and possibly represent more than one taxon. Abaxial side of leaflets is either very sparsely hirsute (almost entirely confined to the veins) or (sub-)glabrous and might be ascribable to var. elata and var. glabrescens (Franch. et Savat.) Pojark. (syn.: A. elata var. mandshurica (Rupr. et Maxim., A. chinensis L. var. glabrescens (Franch. et Savat.) C.K. Schneider, A. spinosa L. var. glabrescens Franch. et Savat.) respectively (sensu Xiang & Lowry 2007). Wen (1994, 2004) describes four varieties of Aralia elata. In his treatment most Belgian collections match var. mandshurica best: leaflets lighter green abaxially (slightly glaucous), echinulate on the veins but otherwise glabrous,…. Faulkner (1939) already experienced that this taxon was the more hardy variety and Frodin & Govaerts (2003) explicitelly state that var. mandshurica is widely cultivated in Europe and elsewhere. Typical var. elata, with very characteristic pubescent to densely pubescent abaxial leaf surfaces, probably has not been recorded as an escape in Belgium so far.
In the British Isles, the closely related Aralia chinensis has been observed. According to Stace (2010) the British plants belong to var. nuda Nakai. Belgian plants with leaflets (sub-) glabrous beneath would key out there. However, following Frodin (1997) and Wen (2004), this is a mere synonym of Aralia elata var. elata.
Finally, another closely related but American species, Aralia spinosa L., is known to have occurred self-seeding in the British Isles (Clement & Foster 1994). However, claims for this species often turned out to be in error for Aralia elata (see Berg & al. 2009 for Austria and Moore & al. 2009 for the U.S.A.).
Selected literature
Adolphi K. (1995) Neophytische Kultur- und Anbaupflanzen als Kulturflüchtlinge des Rheinlandes. Nardus 2: 272 p.
Berg C., Heber G. & Drescher A. (2009) Aralia elata (Miq.) Seem. – eine neue invasive Art? Mitt. Naturw. Ver. Steiermark 139: 135-147.
Clement E.J. & Foster M.C. (1994) Alien plants of the British Isles. BSBI, London: XVIII + 590 p.
Faulkner R.P. (1939) Aralia chinensis. Gard. Chron. III, 106: 304.
Frodin D.G. (1997) Aralia. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 5. Cambridge University Press, Cambridge: 370-372.
Frodin D.G. & Govaerts R. (2003) World checklist and bibliography of Araliaceae. Royal Botanic Gardens, Kew: 444 p.
Gausmann P., Haeupler H. & Adolphi K. (2017) Verwilderungen von Aralia elata, Fraxinus pennsylvanica und Juglans ailantifolia im Mittleren Ruhrgebiet (Nordrhein-Westfalen). Florist. Rundbr. 51: 108-127. [available online at: https://www.researchgate.net/publication/324029802_Verwilderungen_von_Ar...
Hohla M. (2012) Bromus sitchensis – neu für Österreich, Plantago coronopus - neu für Oberösterreich sowie weitere Beiträge zur Kenntnis der Flora des Innviertels. Stapfia 97: 180-192.
Hohla M. (2017) Die Hoge Aralie (Aralia elata) - eine neue Art der Adventivflora Bayerns. Ber. Bayer. Bot. Gesell. 87: 208-212.
Moore G., Glenn S.D. & Ma J. (2009) Distribution of the native Aralia spinosa and non-native Aralia elata (Araliaceae) in the northeastern United States. Rhodora 111: 145-154.
Sato S. & Sakai A. (2004) Fruit foraging process and seed dispersal of Aralia elata by birds. Applied Forest Sc. 13(2): 111-114.
Stace C. (2010) New flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.
Verhaeghe P. (1999) Les plantes ligneuses exotiques subspontanées: découverte d’un Paulownia tomentosa dans le Parc Léopold à Bruxelles. Belgische Dendrologie 1999: 39-44.
Wen J. (1994) New taxa and nomenclatural changes in Aralia (Araliaceae). Novon 4(4): 400-403.
Wen J. (2004) Systematics and biogeography of Aralia L. Dimorphanthus (Miq.) Miq. (Araliaceae). Cathaya 15-16: 1-187.
Xiang Q. & Lowry P.P. (2007) Araliaceae. In: Wu Z.Y. & al. (eds.), Flora of China, vol. 5. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis: 435-491.