2. Diplotaxis virgata (Cav.) DC. (W-Medit.) – A rare but increasing, always ephemeral alien. First recorded as a grain alien in 1997 (Deinze, Gent and Turnhout; see Verloove & Vandenberghe 1998). Subsequently frequently recorded as such (often in abundance), for instance several times on a railway yard in the port of Gent (along with numerous other grain aliens from southwestern Europe). Since 2008 also regularly seen as a weed in containers with imported olive trees (Hoste & al. 2009).
Diplotaxis virgata is an inconspicuous yellow crucifer that might easily be overlooked. Most characteristic are the seeds that are disposed in two rows and the hispid indumentum. Several other closely related (micro-) species occur as weeds of arable land in southwestern Europe (see Martínez Laborde 1993, 2018). However, Belgian plants have patent, hispid hairs and non-cucullate sepals and belong to genuine Diplotaxis virgata.
References
Hoste I., Verloove F., Nagels C., Andriessen L. & Lambinon J. (2009) De adventievenflora van in België ingevoerde mediterrane containerplanten. Dumortiera 97: 1-16.
Martínez Laborde J.B. (1993) Diplotaxis. In: Castroviejo S. & al. (eds), Flora Iberica Vol. 4. Consejo Superior de Investigaciones Científicas, Madrid : 346-362.
Martínez Laborde J.B. (2018) Taxa related to Diplotaxis virgata (Brassicaceae) in northwest Africa. Phytotaxa 371(3): 205-216.
Verloove F. & Vandenberghe C. (1998) Nieuwe en interessante voederadventieven voor de Belgische flora, hoofdzakelijk in 1997. Dumortiera 72: 18-36.