Hedera colchica (K. Koch) K. Koch (Caucasus) – A very rare but increasing escape from cultivation or garden throw-out. Reported as naturalised in Lambermont in 1955 but obviously long overlooked elsewhere. Increasingly recorded since 2005 and at present known from several, widely scattered locations, for instance in Angleur (Sart Tilman), Bellem (Aalter), Diksmuide and Kortrijk. Hedera colchica persists very well and is locally naturalised, sometimes abundantly so. It is found in woodland (frequently in the vicinity of habitations), neglected parks or along disused railway tracks.
Hedera colchica is a very variable species. It is easily recognised by its strong-scent when crushed (strong umbellifer-like smell), thick, large and leathery leaves, often with distinctly inrolled margins (giving the plant an untidy, withered appearance). At least part of the populations (for instance in Angleur and Diksmuide) belong to the cultivar ‘Dentata’, characterised by leaf margins with small but distinct teeth (leaf margins usually entire in typical Hedera colchica). Such plants were initially erroneously ascribed to Hedera algeriensis (Verloove 2006). The latter is surely less hardy, is not strong-scented when crushed and has distinctly lobed leaves that are often broader than long.
Selected literature:
Rutherford A., McAllister H.A. & Mill R.R. (1993) New ivies from the Mediterranean area and Macaronesia. Plantsman 15: 115-128.
Verloove F. (2006) Catalogue of neophytes in Belgium (1800-2005). Scripta Botanica Belgica 39: 89 p.