Trachelium L.
Trachelium is a genus of seven Mediterranean species (only three in Europe; see Tutin 1976). One species, Trachelium caeruleum, is a rather popular ornamental and is much used as a cut flower.
Literature
Buser R. (1894) Contributions à la connaissance des Campanulacées. Genus Trachelium L. revisum. Bull. Herb. Boiss. 2(8): 501-532.
Holverda W., van Moorsel R. & Duistermaat L. (2009) Nieuwe vondsten van zeldzame planten in 2005, 2006 en ten dele 2007. Gorteria 34: 1-40.
Jäger E.J., Ebel F., Hanelt P. & Müller G. (eds.) (2008) Rothmaler Band 5. Exkursionsflora von Deutschland. Krautige Zier- und Nutzpflanzen. Springer Verlag, Berlin: 880 p.
Tutin T.G. (1976) Trachelium. In: Tutin T.G. & al. (eds.), Flora Europaea, vol. 4. Cambridge University Press, Cambridge: 94-95.