In much of Greece the single Oxalis pes-caprae ("bermuda clover" or "bermuda buttercup") is widespread and completely out of control, carpeting open spaces and olive groves to the virtual exclusion of wild flowers that bloom at the same time. As Alberto says, glyphosate does eliminate it, but those who rely on non-chemical methods find it virtually impossible to exclude this pest from gardens in areas that are infested with it.
Alisdair - did we see that Jordan [MGS trip March 2020] is almost free of Oxalis ? Here in Cyprus it is now spreading and flowering yellow everywhere at this time of year. What to do? Lilian, Cyprus. xx