Trifolium echinatum Bieb. (syn.: T. supinum Savi, T. procerum Rochel, T. trichostomum Godr., T. reclinatum Waldst. et Kit.) (SE-Eur., SW-As.) – A rare and ephemeral alien, much decreasing in the past decades. Probably first recorded in a road verge in Niel in 1904 (a single specimen, vector of introduction obscure). Subsequently regularly seen in widely scattered locations, for instance in Andrimont (1954-55), Antwerpen-Linkeroever (1943), Berchem (1958), Dison (1946), Fays (1933), Vorst (1907), etc. Recorded once as a wool alien in Lambermont in 1908. Apparently most recently seen in a newly sown road verge in Wiers in 1991 (as Trifolium alexandrinum) and as grain alien in the Ghent port area in 2018. A young specimen from a garden in Mechelen (introduced with carrot seed) in 1985 possibly also belongs here. Most records are from waste land and are possibly related with cereals (including birdseed).
Lawalrée (1961) ascribed the Belgian collections to subsp. supinum (Savi) Aschers. et Graebn. (syn.: Trifolium supinum Savi) but this taxon is now included in the variability of T. echinatum subsp. echinatum (Zohary & Heller 1984; see also Euro+Med Plantbase).
Selected literature:
Katznelson J. (1971) Population studies in annual clovers. Israel J. Bot. 20 (4): 244-262.
Lawalrée A (1961) Papilionaceae. In: Robyns W. (ed.), Flore Générale de Belgique, vol. 4, fasc. 1. Jardin Botanique de l’Etat, Bruxelles: 9-134.
Zohary M. & Heller D. (1984) The genus Trifolium. Israel Academy of Sciences and Humanities, Jerusalem: 606 p.