Ulex L.

Ulex is a complex genus of ca. 15 species from western Europe and northwestern Africa. One species, Ulex europaeus L., is native in Belgium as well. Few species, including all those that have been recorded so far in Belgium, are also cultivated as ornamentals or for erosion control (Maxwell 1995).

Ulex europaeus was originally confined to slightly acidic, poor, sandy or peaty soils. Its native status in Belgium long remained questionable (see Leurquin & Martin 2013 for an interesting discussion). Lawalrée (1961) still rejected its nativeness. It was formerly sometimes cultivated for forage or for other purposes. At present Ulex europaeus is still introduced in places where it is not native in Belgium. All of this severely affects its distribution pattern in Belgium.

1. Bracteoles (1,5-) 2-4 mm wide. Wings distinctly longer than keel. Spines rigid, deeply grooved. Calyx 10-18 mm long, with long patent and short appressed hairs (native) === Ulex europaeus

1. Bracteoles 0,5-1(-1,5) mm wide. Wings subequal to the keel. Spines more slender, faintly grooved or merely striate. Calyx 6,5-12(-14) mm long, solely with short appressed hairs === 2

2. Calyx mostly more than 10 mm long (usually 10-12 mm). Standard usually exceeding calyx by more than 2 mm. Bracteoles 0,75-1 mm wide === 1. Ulex gallii

2. Calyx mostly less than 10 mm long (usually 7-10 mm). Standard usually exceeding calyx by less than 2 mm. Bracteoles 0,5-0,75 mm wide === 2. U. minor



Ainouche A., Bayer R.J., Cubas P. & Misset M.T. (2003) Phylogenetic relationships within tribe Genisteae (Papilionoideae) with special reference to genus Ulex. In: Klitgaard B. & Bruneau A. (eds.), Advances in legume systematics. Part 10, Higher level systematics. Kew: Royal Botanic Gardens, Kew: 239-252. [available online at:  


Cubas P. (2000) Ulex. In: Talavera S. & al. (eds.), Flora Iberica, vol. 7(I). Real Jardín Botánico, Madrid: 212-239.

Cubas P. & Pardo C. (1988) Morfología de las semillas del género Ulex L. (Genisteae, Papilionoideae). Lagascalia 15(extra): 275-283. 

Gloaguen J.C. (1986) Les Ajoncs de Bretagne. Bull. Soc. Bot. France, Lett. Bot. 133: 363-381.

Guinea E. & Webb D.A. (1968) Ulex. In: Tutin T.G. & al. (eds.), Flora Europaea, vol. 2. Cambridge University Press, Cambridge: 102-103.

Lawalrée A (1961) Papilionaceae. In: Robyns W. (ed.), Flore Générale de Belgique, vol. 4, fasc. 1. Jardin Botanique de l’Etat, Bruxelles: 9-134.

Leurquin J. & Martin P. (2013) L'ajonc d'Europe, Ulex europaeus, et son degré de spontanéité en Belgique. Nat. Mosana 66(1): 1-9.

Maxwell H.S. (1995) Ulex. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 4. Cambridge University Press, Cambridge: 550.

Proctor M.C.F. (1967) Notes and keys of papers read at the local flora writer's conference, Bristol, 1966. The British species of Ulex. Bot. Soc. Brit. Isles Proc. 6: 379-380.

Rothmaler W. (1941) Revision der Genisteen: I. Monographien der Gattungen um Ulex. Bot. Jahrb. 72: 69-116.

Sell P. & Murrell G. (2009) Flora of Great Britain and Ireland. Vol. 3 Mimosaceae – Lentibulariaceae. Cambridge University Press, Cambridge: XXVIII + 595 p.

Webb D.A. (1967) Some taxonomic notes on Ulex s.l. Feddes Repert. 74: 4-6.    

Taxonomic name: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith