Native to Australia and New Zealand, pirri-pirri bur, Acaena novae-zelandiae, is a short, creeping plant popular in container planting schemes and rockeries. It forms dense mats of lobed bronze leaves, from which ball-like heads of hooked seeds (burs) appear.
In recent years it has spread to the wild through seed and the dumping of garden material. It is now found in a variety of wild habitats including sand dunes, cliffs, heaths and disused railways, where it poses a threat to native plants. It's easily spread by seed via its hooked bur, and can be invasive.
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Acaena and wildlife
Acaena has no particular known value to wildlife in the UK.