Trifolium sylvaticum Gérard ex Loisel. (syn.: T. smyrnaeum Boiss., T. lagopus Willd.) (Medit.) – An exceptional and ephemeral alien. A single individual was found in 2016 on a demolition site in the city of Ghent. This species obviously germinated from an old seed bank but its initial vector of introduction is obscure. It was found along with other interesting but rare aliens like Glaucium grandiflorum, Modiola caroliniana, Vicia cuspidata, etc.
Trifolium sylvaticum was cited from Belgium in the monograph of the genus (Zohary & Heller 1984), subsequently followed by author authors (e.g. Muñoz Rodrígues & al. 2000). However, this species is definitely not native in Belgium nor has it, to our knowledge (e.g. Verloove 2006), ever been recorded as an alien.
This species was long known as Trifolium smyrnaeum and it was referred to under that name in Flora Europaea (Coombe 1968; see also Hossain 1961). However, T. sylvaticum is the earliest valid name available for this species (Zohary & Heller 1984).
Contrary to some floras (e.g. Townsend 1974) capitula are not sessile in this species but borne on peduncles up to 7 cm long (Muñoz Rodrígues & al. 2000).
Trifolium sylvaticum is a very rare alien in western Europe. There seem to be no records, for instance, from the British Isles (Clement & Foster 1994).
Selected literature:
Clement E.J. & Foster M.C. (1994) Alien plants of the British Isles. BSBI, London: XVIII + 590 p.
Coombe D.E. (1968) Trifolium. In: Tutin T.G. & al. (eds.), Flora Europaea, vol. 2. Cambridge University Press, Cambridge: 157-172.
Hossain M. (1961) A revision of Trifolium in the nearer East. Notes Roy. Bot. Gard. Edinburgh 23: 387-481.
Kolev I.D. & Sedmakova Louchanska E. (1972) A karyological study of Trifolium arvense L., T. preslianum Boiss. and T. smyrnaeum Boiss. in Bulgaria. Compt. R. Acad. Agric. Georgi Dimitrov 5(1): 39-43.
Muñoz Rodrígues A., Devesa J.A. & Talavera S. (2000) Trifolium. In: Talavera S. & al. (eds.), Flora Iberica, vol. 7(II). Real Jardín Botánico, Madrid: 647-719. [available online at: http://www.floraiberica.es/floraiberica/texto/pdfs/07_38%20Trifolium.pdf]
Nemati M. (2005) Trifolium sylvaticum Eig. (Papilionaceae), a new record for the flora of Iran. Iranian J. Bot. 11(1): 27-29. [available online at: http://journals.areo.ir/article_102859_85bd73b1b255afbde15b38ef5d40ec60....
Townsend C.C. (1974) Leguminales. In: Townsend C.C. & Guest E. (eds.), Flora of Iraq, vol. 3. Min. Agric. Agrar. Ref., Baghdad: 662 p.
Verloove F. (2006) Catalogue of neophytes in Belgium (1800-2005). Scripta Botanica Belgica 39: 89 p. [available online at: http://alienplantsbelgium.be/sites/alienplantsbelgium.be/files/tabel_2.pdf]
Zohary M. & Heller D. (1984) The genus Trifolium. Israel Academy of Sciences and Humanities, Jerusalem: 606 p.