Campanula poscharskyana Degen (ex-Yugoslavia) – A very rare but increasing, locally naturalised escape from cultivation. Discovered in abundance on an old wall in Brugge (Minnewaterpark) in 2001 (Verloove 2002, 2006); here obviously well naturalised. Since 2007 also found in other cities, mainly in Antwerpen and Gent, and doubtlessly elsewhere too. Campanula poscharskyana usually grows in stony, sun-exposed or partly shaded habitats: old walls, cracks in pavement or foot of walls.
Some Belgian populations of Campanula poscharskyana are fairly atypical and probably represent hybrids or cultivars (for instance from Begijnhoflaan in Gent). They are more vigorous with often long trailing stems and are glabrescent.
Campanula poscharskyana is possibly confused with C. portenschlagiana in Belgium (although it surely is much rarer, in cultivation and as an escape). Its corollas are much deeper lobed and leaves are double serrate. Confusion is more likely with Campanula fenestrellata (see Dunkel 2006 and Ronse 2006 for more details about their separation).
Selected literature
Dunkel F.-G. (2006) Neues oder Bemerkenswertes zur Flora Bayerns – Achillea roseoalba, Orobanche amethystea und andere Funde. Ber. Bayer. Bot. Ges. 76: 151-168.
Grenfell A.L. (1983) Aliens and adventives. Adventive News 24. BSBI News 33: 10-11.
Hillegers H.P.M. & Weeda E.J. (2003) Klokjes op muren en rotsen in Limburg. Natuurh. Maandbl. 93: 61-70.
Ronse A. (2006) Campanula fenestrellata: eerste waarneming van verwildering in België. Dumortiera 90: 10-12.
Verloove F. (2002) Ingeburgerde plantensoorten in Vlaanderen. Mededeling van het Instituut voor Natuurbehoud n° 20: 227 p.
Verloove F. (2006) Campanula poscharskyana. In: Van Landuyt W., Hoste I., Vanhecke L., Van den Bremt P., Vercruysse W. & De Beer D., Atlas van de flora van Vlaanderen en het Brussels gewest. Instituut voor Natuur- en Bosonderzoek, Nationale Plantentuin van België en Flo.Wer: 219.