Acanthospermum hispidum DC. (S-Am.) – A rare and ephemeral alien. Recorded between 1997 and 2005 as a soybean alien in port areas in Antwerpen and Gent, mostly on unloading quays, near grain mills and on grain dumps. It was usually seen in small number and seemed very reluctant to flower in western Europe.
There are but very few European records of Acanthospermum hispidum (e.g. Karlsson 1997 for Scandinavia). Two similar species have been recorded as wool aliens in the British Isles (Clement & Foster 1994).
Even in the absence of flowers Acanthospermum hispidum is a rather characteristic species: its leaves are opposite, rhombic in outline and gland-dotted.
Selected literature:
Clement E.J. & Foster M.C. (1994) Alien plants of the British Isles. BSBI, London: XVIII + 590 p.
Karlsson T. (1997) Förteckning över svenska kärlväxter. Svensk Bot. Tidskr. 91: 241-560.
Mirashi M.V. & Bhogaenkar P.Y. (1974) Anatomy of Acanthospermum hispidum DC. Proc. Indian Acad. Sci., B 79(4): 154-159.
Verloove F. (2003) Graanadventieven nieuw voor de Belgische flora, hoofdzakelijk in 1999 en 2000. Dumortiera 80: 45-53. [available online at: http://alienplantsbelgium.be/sites/alienplantsbelgium.be/files/dum80p45.pdf]