Hypericum olympicum L. (Balkans, Turkey) – A very rare escape from cultivation. Discovered in 2014 in two localities, at first in Balen (Mol) in a former camping site, possibly as a mere relic of cultivation. Subsequently also seen at a foot of a tree in Gent, obviously self-sown from a nearby plantation.
Hypericum olympicum is an attractive bushy perennial that is increasingly planted as an ornamental. It is known to easily reproduce from seed and tends to naturalize locally in the British Isles (Clement 2002) and has also been recorded, for instance, in Scandinavia (Fröberg 2010) and Germany (Brandes 2011). It will probably increase in Belgium also and may be able to establish itself in suitable habitats (i.e., dry and sunny places).
Brandes D. (2011) Neufunde von Neophyten im Stadtgebiet von Braunschweig. Braunschweiger Naturkundliche Schriften 10(1): 79-96. [available online at: http://digisrv-1.biblio.etc.tu-bs.de:8080/docportal/servlets/MCRFileNodeServlet/DocPortal_derivate_00021233/Brandes-Neufunde_Neophyten_Stadtgebiet_Braunschweig.pdf]
Clement E.J. (2002) Hypericum olympicum in the British Isles. B.S.B.I. News 90: 47. [available online at: http://archive.bsbi.org.uk/BSBINews90.pdf]
Fröberg L. (2010) Hypericum. In: Jonsell B. & Karlsson T. (eds.), Flora Nordica, vol. 6. The Swedish Museum of Natural History, Stockholm: 5-12. [available online at: http://www.floranordica.org/Review/-Review_public/accounts/Hypericaceae.html#olympicum]
Robson N.K.B. (1980) Hypericum olympicum - wild and cultivated. The Plantsman 1(4): 193-200.
Robson N.K.B. (2010a) Studies in the genus Hypericum L. (Hypericaceae) 5(1). Sections 10. Olympia to 15/16. Crossophyllum. Phytotaxa 4: 5-126.