Echinops is an Old World genus of ca. 120 species, mostly native to Eurasia (some also in northern and eastern Africa) (Mabberley 2008). Recent molecular phylogenetic studies demonstrated that it is monophyletic (Garnatje & al. 2005, Sánchez-Jiménez I. & al. 2010). None are native in Belgium. Many species of Echinops are very attractive and several are cultivated as ornamentals in Europe (Cann 2000, Jäger & al. 2008), although only few are really widespread in cultivation. In general, Echinops is nowadays probably less frequently cultivated in Belgium and probably decreasing in the wild as well. It is sometimes cultivated by bee-keepers.
The identification of Echinops long remained critical in Belgium and most herbarium sheets bear more than one name. Lawalrée & Wechuysen (1979) finally corrected most determinations. In addition to the three species treated below, Echinops ritro L. has been claimed as an alien in Belgium (Westerlo, Vilvoorde) but this requires confirmation. It usually has bright blue and smaller heads and more finely dissected (2-pinnatifid), more or less leathery leaves. It might have been confused with Echinops bannaticus.
1. Upper surface of leaves and stem eglandular. Involucral bracts bent at apex === 2. Echinops exaltatus
1. Upper surface of leaves and/or upper part of stem with sessile glands. Involucral bracts straight at apex === 2
2. Involucral bracts and upper part of stem with sessile glands. Heads 30-60 cm across, pale greyish-blue. Plant up to 200 cm tall === 3. E. sphaerocephalus
2. Involucral bracts and stem eglandular. Heads 25-50 cm across (or slightly larger in cultivars), bluish. Plant up to 120 cm tall (or taller in cultivars) === 1. E. bannaticus
Literature:
Cann D.C.G. (2000) Echinops. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 6. Cambridge University Press, Cambridge: 519-520.
Garnatje T., Susanna A., Garcia Jacas N., Vilatersana R. & Vallès J. (2005) A first approach to the molecular phylogeny of the genus Echinops (Asteraceae): sectional delimitation and relationships with the genus Acantholepis. Folia Geobot. 40: 407-419.
Hendrych R. (1987) Einige Bemerkungen zu den Echinops-Arten in der Tschechoslowakei. Preslia 59: 135-154.
Hensen K.J.W. (1965) Het Echinops-sortiment van botanische tuinen en Nederlandse vasteplantenkwekers. Belmontia 9(4): 85-96.
Jäger E.J., Ebel F., Hanelt P. & Müller G. (eds.) (2008) Rothmaler Band 5. Exkursionsflora von Deutschland. Krautige Zier- und Nutzpflanzen. Springer Verlag, Berlin: 880 p.
Karlsson T. (1986) Tre arter av Echinops, bolltistel, förvildade i Sverige. Svensk Bot. Tidskr. 80: 279-288.
Kožuharov S. (1976) Echinops. In: Tutin T.G. & al. (eds.), Flora Europaea, vol. 4. Cambridge University Press, Cambridge: 212-214.
Krumbiegel A. & Klotz S. (1995) Bestimmungsschlüssel spontan und synanthrop vorkommender Arten der Gattung Echinops in Mitteldeutschland. Flor. Rundbr. 29(2): 109-112.
Lawalrée A. & Wechuysen R. (1979) Les Echinops de Belgique. Dumortiera 12: 14-15.
Ludwig W. (1989) Über Kügeldistln (Echinops-Arten) in Hessen. Hess. Flor. Briefe 38: 2-6.
Mabberley D.J. (2008) Mabberley’s plant-book (3th ed.). Cambridge University Press, Cambridge: XVIII + 1021 p.
Sánchez-Jiménez I., Lazkov G.A., Hidalgo O. & Garnatje T. (2010) Molecular systematics of Echinops L. (Asteraceae, Cynareae): a phylogeny based on ITS and trnL-trnF sequences with emphasis on sectional delimitation. Taxon 59(3):698-708.
Sell P. & Murrell G. (2006) Flora of Great Britain and Ireland. Vol. 4 Campanulaceae – Asteraceae. Cambridge University Press, Cambridge: XXVIII + 624 p.
Walter E. (1991) Zum Vorkommen und zur Verbreitung der Kugeldistel-Gattung Echinops in Oberfranken. Ber. Naturforsch. Ges. Bamberg 66: 17-44.