Acaena novae-zelandiae (bidi-bidi, biddy-biddy, bidgee-widgee, or piri-piri-bur) is an ornamental plant native to New Zealand and Australia. It can also be found elsewhere as an introduced species, and is considered a noxious weed in some areas, such as Hawaii and California. The common name bidi-bidi is a corruption of the Māori name for this plant, piripiri.