Onopordum illyricum

{{Short description|Species of flowering plant}}

{{speciesbox

|image = Onopordum illyricum near Holbrook NSW Australia.jpg

|genus = Onopordum

|species = illyricum

|authority = L.

}}

Onopordum illyricum is a species of thistle known by the common name Illyrian thistle,{{BSBI 2007 |accessdate=2014-10-17 }} or Illyrian cottonthistle.{{PLANTS|id=ONIL|taxon=Onopordum illyricum|accessdate=30 January 2016}} It is native to southwestern Europe, but has been introduced into Australia and California, where it has become a noxious weed.

The plant is a biennial herb producing an erect, branching, winged, spiny stem known to exceed two meters in maximum height. The spiny leaves may be up to {{convert|50|cm|in|0}} long and are divided into deep toothed lobes. The inflorescence bears several large flower heads each up to {{convert|7|cm|in|0}} wide. They are lined with spiny, woolly to cobwebby phyllaries and bear many narrow glandular purple flowers each about {{convert|3|cm|in}} long. The fruit is a cylindrical achene {{convert|4|or|5|mm|in}} long topped with a white pappus {{convert|1|cm|in}} in length.