Chaerophyllum byzantinum Boiss. (SE-Eur., SW-As.) – A very rare and possibly ephemeral escape from cultivation. Recorded only twice so far in Belgium. First seen in Cheratte in 1989 (some specimens in and near an abandoned garden), obviously as an escape from cultivation (Lambinon & al. 1990). In 2016, a large population was discovered in similar circumstances in Genk.
The similar (and sometimes considered to be conspecific) Chaerophyllum aromaticum L. is probably more often cultivated and might also occur as an escape. Its leaf-lobes are more coarsely serrate and obliquely cuneate at base and acute-acuminate at apex (versus finely serrate leaf-lobes that are subcordate at base and rounded at apex in Chaerophyllum byzantinum) (see Saarinen & al. 2013). Both these species are evidently closely related but appear to be distinct genetically (Downie & al. 2000).
 |
 |
 |
 |
Selected literature:
Downie S.R., Katz-Downie D.S. & Spalik K. (2000) A phylogeny of Apiaceae tribe Scandiceae: evidence from nuclear ribosomal DNA internal transcribed spacer sequences. American Journal of Botany 87: 76-95. [available online at: http://www.life.illinois.edu/downie/AJB2000A.pdf]
Kopecky K. (1985) Der Apophytisierungsprozeß am Beispiel der Saumgesellschaften mit Chaerophyllum aromaticum L. in der Tschechoslowakei. Tuexenia 5: 127-130.
Lambinon J., Rousselle J. & Van Den Sande G. (1990) Une surprenante Ombellifère introduite dans la région liégeoise. Nat. Mosana 43: 102-103.
Ludwig W. (1987) Chaerophyllum byzantinum Boiss. als türkische Nutzpflanze in Werdorf (MTB 5416/21). Hess. Flor. Briefe 36(2): 18.
Neushauslova-Novotna Z. (1974) Die Verbreitung von Chaerophyllum aromaticum L. in der Tschechischen Sozialistischen Republik (CSR) (in Czech). Zpravy Cesk. Bot. Spol. 9(2): 79-94.
Raabe U. (2001) Der Gewürz-Kälberkropf (Chaerophyllum aromaticum L.) auf Rügen - neu für Mecklenburg-Vorpommern. Botanischer Rundbrief für Mecklenburg-Vorpommern 35: 27-28.
Saarinen K., Jantunen J. & Miettinen M. (2013) Tuoksukirveli tuorein itälisä Imatran (ES) puuplaanin lajistoon (Chaerophyllum aromaticum discovered in SE Finland). Lutukka 29(3): 88-91.