Euonymus fortunei (Turcz.) Hand.-Mazz. (syn.: E. hederaceus Champ. ex Benth.) (E-As.) – A rare but increasing, locally more or less persistent escape from cultivation (mostly a garden throw-out, only rarely self-sown). First detected in 1986 in Nederokkerzeel near to the Torfbroek nature reserve in a rather remote and natural habitat (spontaneous woodland on damp, calcareous substrate). In 2004 also discovered under shrubs in a park in Ieper (several m², not planted). Seen as self-sown on the cemetery Campo Sancto in Gent in 2007 (cracks in concrete). Reported as freely flowering and fruiting in a nature reserve in Zoersel (Zoerselbos) in 2008. Also in Hoge Beemortel in Putte (2008) and under Picea (obviously self sown) in Roeselare (2011). In many of these places the species' presence was subsequently confirmed and, in addition, it was found in rather numerous new localities. Since 2009 it has also been known from Wallonia (for instance in Bois de Baudour, Quartier de la Charbonnière). Possibly neglected elsewhere.
Euonymus fortunei is still frequently planted for ground cover. It frequently proliferates and is often discarded, for instance in wood margins. In suitable habitats (more or less damp, shady places) it easily becomes established. More populations will probably come to light in a near future and a wider naturalisation seems very likely.
Euonymus fortunei is a very variable species. Most ornamental plants – including those found in the wild in Belgium so far – probably belong to var. radicans (Siebold ex Miq.) Rehd. (syn.: E. radicans Siebold ex Miq. var. acutus Rehd.), a trailing shrub, often with variegated leaves.
According to Ma (2001) this species is better referred to as Euonymus hederacea.
Adolphi K. & Kasperek G. (2004) Euonymus fortunei und Euonymus japonica – zwei immergrüne Spindelsträucher mit Verwilderungstendenz. In: 38. Hessischer Floristentag - Tagungsbeiträge. Amt für Stadtökologie – Abt. Umwelt der Wissenschaftsstadt Darmstadt. Schriftenreihe 17(3): 30-37 (also on: www.uni-giessen.de).
Ma J. S. (2001) A Revision of Euonymus (Celastraceae). Thaiszia 11: 1-264.
Mattingly K.Z., McEwan R.W., Paratley R.D., Bray S.R., Lempke J.R. & Arthur M.A. (2016) Recovery of forest floor diversity after removal of the nonnative, invasive plant Euonymus fortunei. Journ. Torrey Bot. Soc. 142(3): 103-116. [available online at: https://www.researchgate.net/publication/299416781_Recovery_of_forest_fl...