Vinca is a genus of seven species native to Eurasia and N-Africa. One species, Vinca minor L., is probably locally native in Belgium although seeds are rarely produced. It is still popular as a garden plant (ground cover) and many populations are surely non-natural. An overview of its cultivars is provided by Stearn (2000).In addition to Vinca major and V. minor some related species might have been overlooked. Vinca difformis Pourr. is very reminiscent of V. major but its leaves and sepals are completely hairless (with minute marginal hairs in the latter).
1. Sepals ciliate, 10-15 mm long. Corolla 30-50 mm across. Leaves ovate to broadly ovate, the margins ciliate === 1. Vinca major
1. Sepals glabrous, 2-5 mm long. Corolla 20-30 mm across. Leaves lanceolate to elliptical, with glabrous margins (native) === V. minor
Literature
Atzei A.D. & Picci V. (1977) Ricerche sul genere Vinca. Archivio Botanico 51: 157-210.
Brennenstuhl G. (2008) Zur Einbürgerung von Vinca- und Miscanthus-Taxa – Beobachtungen im Gebiet um Salzwedel. Mitt. Florist. Kart. Sachsen-Anhalt 13: 77-84.
Hensen K.J.W. (1980) Taxonomie en nomenclatuur van het Vincasortiment. Groen 36: 187-194.
Lawrence G.H.M. (1959) Vinca and Catharanthus. Baileya 7: 113-119.
Pichon M. (1951) Classification des Apocynacées. 22. Les espèces du genre Vinca. Bull. Mus. Nat. Hist. Natl., ser. 2, 23: 439-444.
Stearn W.T. (1973) A synopsis of the genus Vinca including its taxonomic and nomenclatural history. In: Taylor W.I. & Farnsworth N.R. (eds.), The Vinca alkaloids: botany, chemistry, and pharmacology. M. Dekker, New York: 19-94.
Stearn W.T. (2000) Vinca. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 6. Cambridge University Press, Cambridge: 38-40.