Barbarea verna (Mill.) Aschers. (syn.: B. praecox (Smith) R. Brown) (S-Eur., W-As.) – A rare and usually ephemeral or probably locally naturalized alien. Formerly sometimes grown as a vegetable (salad). First collected in Heusden in 1860 and soon afterwards in several other locations in the second half of the 19th century, mainly around Liège (Meuse, Ourthe). In the past decades apparently increasing and around Ghent more or less locally established (for instance in Ledeberg and in the port area). Also reported as more or less naturalized from an abandoned railway station in Braine-le-Comte (Depasse 1990). Barbarea verna is usually found on waste land, in road verges or on railway banks. Some recent records are obviously associated with cereals and birdseed.
Depasse S. (1990) Barbarea verna et quelques autres plantes intéressantes à la gare de Braine-le-Comte (province de Hainaut). Nat. Mosana 43(4): 128.
Van der Ham R.W.J.M. (1982) Barbarea intermedia Bor. en Barbarea verna (Mill.) Aschrs. in Nederland. Gorteria 11(2): 36-39. [available online at: http://natuurtijdschriften.nl/download?type=document&docid=536450]