Ballota L.
Ballota is a genus of ca. 30 Old World species. They are mainly distributed in Eurasia and the Mediterranean area (an additional species in South Africa). About five species are sometimes cultivated as ornamentals in gardens in Europe but most are confined to the warmer areas. One species, Ballota nigra (at least subsp. meridionalis (Béguinot) Béguinot; syn.: subsp. foetida Hayek), is native in Belgium. Another subspecies, subsp. nigra, is sometimes found as an alien.
Molecular data strongly suggest that Ballota is paraphyletic (Scheen & al. 2010). Its generic boundaries are in need of revision.
Literature:
Davis P.H. & Doroszenko A. (1982) Ballota. In: Davis P.H. (ed.), Flora of Turkey and the East Aegean Islands, Vol. 7. Edinburgh University Press, Edinburgh: 156-165.
Lambinon J. & Verloove F. (avec coll. Delvosalle L., Toussaint B., Geerinck D., Hoste I., Van Rossum F., Cornier B., Schumacker R., Vanderpoorten A. & Vannerom H.) (2012) Nouvelle Flore de la Belgique, du Grand-Duché de Luxembourg, du Nord de la France et des Régions voisines (Ptéridophytes et Spermatophytes). Sixième édition. Jardin botanique national de Belgique, Meise: CXXXIX + 1195 p.
Patzak A. (1958) Revision der Gattung Ballota Section Ballota. Ann. Naturhist. Mus. Wien 62: 57-86.
Patzak A. (1959) Revision der Gattung Ballota Section Ballota. Ann. Naturhist. Mus. Wien 63: 33-81.
Patzak A. (1961) Revision der Gattung Ballota Section Ballota. Ann. Naturhist. Mus. Wien 64: 42-56.
Patzak A. (1972) Ballota. In: Tutin T.G. & al. (eds.), Flora Europaea, vol. 3. Cambridge University Press, Cambridge: 149-151.
Poyarkova A.I. (1977) Ballota. In: Shishkin B.K. (ed.), Flora of the U.S.S.R., vol. XXI. Academy of Sciences of the USSR: 137-140.
Scheen A.-C., Bendiksby M., Ryding O., Mathiesen C., Albert V.A. & Lindqvist C. (2010) Molecular Phylogenetics, Character Evolution, and Suprageneric Classification of Lamioideae (Lamiaceae). Annals of the Missouri Botanical Garden 97(2): 191-217.
Sell P. & Murrell G. (2009) Flora of Great Britain and Ireland. Vol. 3 Mimosaceae – Lentibulariaceae. Cambridge University Press, Cambridge: XXVIII + 595 p.
Whiteley A.C. (2000) Ballota. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 6. Cambridge University Press, Cambridge: 203-204.