1. Cullen americanum (L.) Rydb. (syn.: Psoralea americana L., P. dentata DC.) (W-Medit.) – A rare and ephemeral alien. First recorded as a wool alien in the Vesdre valley in 1915. Subsequently seen on dumps in Mechelen in 1953 and 1954 and on waste land in Kessel-Lo in 1966. Collected at several locations in Turnhout in 1970 (dump, waste land and unloading quay for cereals) and again on a dump in 1977. Apparently last recorded on a demolition site in Gent in 2001, along with several other exceptional grain and wool aliens (Verloove & Heyneman 2012).
Cullen americanum mostly grows on dumps and waste land. Its vector of introduction is rarely obvious. Most records are probably associated with cereals (including birdseed; see also Hanson & Mason 1985).
References
Clement E.J. (1978) Adventive news 10. Mixed bag. BSBI News 18: 11-15.
Georges N. (2010) Note sur le Cullen d’Amérique (Cullen americanum (L.) Rydb.), adventice rarement observée en France. Monde Pl. 502: 30-31.
Hanson C.G. & Mason J.L. (1985) Bird seed aliens in Britain. Watsonia 15: 237-252.
Verloove F. & Heyneman G. (2012) Merkwaardige plantencollecties van twee antropogene zaadbanken in Gent (Oost-Vlaanderen, België). Dumortiera 100: 19-24.