Notobasis (Cass.) Cass.
Notobasis is a monotypic genus from the Mediterranean area and Southwest Asia. It is morphologically and cytologically similar to Cirsium but differs in some respects, e.g. the rounded shape and the abaxial detachment area of the achenes. This somewhat isolated morphological situation is confirmed by ITS sequence data (Häffner & Hellwig 1999).
Its single species, Notobasis syriaca, has rarely been recorded as an alien in Belgium.
El Karemy Z. & Zareh M. (1991) Systematic revision of Compositae in Egypt: 8. Tribe Cardueae : Carduus and allied genera. Mitt. Bot. Staatssamml. Munchen 30: 439-457.
Greuter W., Aghababian M. & Wagenitz G. (2005) (1670-1675) Proposals to conserve the names Bellidiastrum, Berkheya, Euryops, Notobasis, Picnomon and Urospermum (Compositae) against six generic names of Vaillant. Taxon 54: 196-198.
Häffner E. & Hellwig F.H. (1999) Phylogeny of the tribe Cardueae (Compositae) with emphasis on the subtribe Carduinae: an analysis based on ITS sequence data. Willdenowia 29: 27-39. [available online at: http://www.bgbm.fu-berlin.de/sites/alienplantsbelgium.bedefault/files/documents/w29Haeffner%2BHellwig.pdf]