Nonea lutea (Desr.) DC. (Russia, Caucasus) – A very rare alien of uncertain origin. Discovered by a roadside in Dilsen-Stokkem in 2004 (initially erroneously as Amsinckia lycopsoides) and confirmed in 2009. In this locality Nonea lutea now behaves like an agricultural weed and abundantly grows in the margin of a barley-field. Similar weedy tendencies were also observed, for instance, in a botanic garden in Austria (Eberwein 2011). In 2018 a small population was found on the verge of a garden (foot of hedge) in Leefdaal.
Nonea lutea somehow looks like a species of Amsinckia but clearly differs in calyx and nutlet characters.
Bernard C. (2001) La nonnée jaune: Nonea lutea (Desrousseaux) DC. en Cote d'Ôr. Monde Pl. 473: 1-2.
Clement E.J. (1977) Aliens and Adventives. B.S.B.I. News 16: 18 (+ frontcover). [available online at: http://archive.bsbi.org.uk/BSBINews16.pdf]
Eberwein R.K. (2011) Pflanzen mit invasivem Potenzial in Botanischen Gärten II: Nonea lutea (Boraginaceae). Carinthia II 201/121: 243-248. [available online at: http://www.landesmuseum.at/pdf_frei_remote/CAR_201_121_0243-0248.pdf]
Lacey W.S. (1977) Letters. (Nonea lutea (Desr.) DC in Bangor.) B.S.B.I. News 17: 28. [available online at: http://archive.bsbi.org.uk/BSBI_News_17.pdf]