Matthiola longipetala (Vent.) DC. subsp. bicornis (Sibth. et Smith) P.W. Ball (syn.: Matthiola bicornis (Sibth. et Smith) DC.) (SE-Eur.) – An exceptional and ephemeral escape from cultivation. Recorded at the foot of a wall in 2005 in Berchem (Antwerpen) and in Brugge in 2013.
This taxon is sometimes included in wildflower seed-mixtures nowadays and might increase in the future (see also Lombard 2009).
References
Lombard A. (2009) Résultats d’herborisations en banlieue parisienne à Ivry-sur-Seine (Val-de-Marne) et ses environs. Monde Pl. 497: 5-11.
Sârbu I., Ştefan N. & Toniuc A. (1993) Matthiola longipetala (Ven) DC. ssp. bicornes (Sibth. et Sm.) P.W. Ball dans la flore de Roumanie. An. Sti. Univ. "Al. I. Cuza" Iasi, Biol. 39: 81-83.