Ononis L.
Ononis is a genus of ca. 75 species, mostly native to Europe, the Mediterranean area, Macaronesia and parts of Africa and western Asia. Two species (of debated taxonomic status) are native in Belgium: Ononis repens L. and O. spinosa L. They are perhaps better treated as two subspecies of one variable species. Fertile, intermediate forms do occur (see also Sell & Murrell 2009). Both taxa are often found in artificial locations where they are not native (mainly railway tracks).
Recent molecular phylogenetic research provided evidence that Ononis is monophyletic but the traditional subgeneric classification was not confirmed (Turini & al. 2010).
1. Corolla yellow. Peduncle longer than the subtending leaf. Plant always spineless. Pod 10-25 mm long (much longer than the calyx) with 4-10 seeds === 2. Ononis natrix
1. Corolla pink. Peduncle shorter than the subtending leaf. Plant spiny or spineless. Pod 6-10 mm long (hardly exceeding the calyx) with 2-3 (-4) seeds === 2
2. Spineless annual. Standard glabrous. Leaves mostly unifoliate === 1. O. alopecuroides
2. Perennial, usually spiny. Standard pilose. Leaves mostly 3-foliate (native) === O. repens and O. spinosa
Additional alien: Ononis mitissima L. was claimed as an alien (Lambinon & al. 2004) but no corresponding herbarium specimen has been located so far (Verloove & Lambinon 2008).
References
Coulot P. & Rabaute P. (2013) Monographie des Leguminosae de France. Tome 3 Tribu des Trifolieae. Bull. Soc. Bot. Centre-Ouest N.S. 40: 760 p.
Devesa J.A. (1988) Estudio taxonómico del género Ononis L. (Leguminosae) en Portugal. Mem. Soc. Brot. 28: 5-53.
Devesa J.A. (2000) Ononis. In: Talavera S. & al. (eds.), Flora Iberica, vol. 7(II). Real Jardín Botánico, Madrid: 590-646.
Erdtmann J. (1964) Zur Verbreitung und Taxonomie der Gattung Ononis in Nordost-Deutschland. Feddes Repert. Spec. Nov. Regni Veg. 69: 103-131.
Ivimey-Cook R.B. (1968) Ononis. In: Tutin T.G. & al. (eds.), Flora Europaea, vol. 2. Cambridge University Press, Cambridge: 143-148.
Krendl F. & Polatschek A. (1987) Die Gattung Ononis L. in Österreich. Verh. Zool.-Bot. Ges. Österreich 122: 77-91.
Lawalrée A (1961) Papilionaceae. In: Robyns W. (ed.), Flore Générale de Belgique, vol. 4, fasc. 1. Jardin Botanique de l’Etat, Bruxelles: 9-134.
Lambinon J., Delvosalle L., Duvigneaud J. (avec coll. Geerinck D., Lebeau J., Schumacker R. & Vannerom H. (2004) Nouvelle Flore de la Belgique, du Grand-Duché de Luxembourg, du Nord de la France et des Régions voisines (Ptéridophytes et Spermatophytes). Cinquième édition. Jardin botanique national de Belgique, Meise: CXXX + 1167 p.
Morton J.K. (1956) Studies on Ononis in Britain. Watsonia 3: 307-316.
Sell P. & Murrell G. (2009) Flora of Great Britain and Ireland. Vol. 3 Mimosaceae – Lentibulariaceae. Cambridge University Press, Cambridge: XXVIII + 595 p.
Širjaev G. (1932) Generis Ononis L., revisio critica. Beih. Bot. Centralbl. 49(2): 381-665.
Stace C. (2010) New flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.
Turini F.G., Bräuchler C. & Heubl G. (2010) Phylogenetic relationships and evolution of morphological characters in Ononis L. (Fabaceae). Taxon 59(4): 1077-1090.
Verloove F. & Lambinon J. (2008) Neophytes in Belgium: corrections and adjustments. Syst. Geogr. Pl. 78: 63-79.