Necessary background for studies in the taxonomy of Onopordum in Australia
P.W. Michael, 5 George Street, Epping, New South Wales, Australia.
In the absence of a recent and informed world revision of Onopordum it is very difficult to ascertain just which taxa occur thoroughly naturalized or as casuals in Australia. Three species, O. acaulon L., O. acanthium L., and O. illyricum L., are commonly listed as widespread and hybrids between the two latter have been suggested. In Flora Europaea, various subspecies of these three species have been included. In the Flora of New South Wales, occurrences of O. acanthium are restricted to O. acanthium ssp. acanthium and of O. illyricum to O. illyricum ssp. illyricum. O. tauricum Willd., O. leptolepis DC. and what I consider to be O. arabicum L. (usually known as O. nervosum Boiss.) have been found or may possibly occur as casuals in Victoria. In this paper, attention is given especially to difficulties in the typification of O. illyricum L. Doubts are expressed as to the validity of using O. illyricum for some of the plants so called in Australia and evidence is given suggesting that other taxa not yet recorded here may be involved. Material is also presented relevant to the origins, cultivation and naturalization of the genus.
Plant Protection Quarterly (1996) 11 (Supplement 2) 239-241.