Creeping perennial from the Rosaceae family, native to New Zealand, where it occupies open grasslands, roadsides, and rocky areas of the montane and subalpine zones of the two main islands.
It forms a creeping and dense mat, with a modest height of 5 to 10 cm, with a particularly flat habit. Its most remarkable feature is the color of its evergreen foliage: pinnate leaves of a bronze-brown to dark purple, sometimes almost chocolate, which give it an unusual visual presence among ground covers.
The flowers are tiny, grouped in small globular heads carried on thin upright peduncles, without particular brilliance. The fruits that follow are little or not spiny — as suggested by its Latin epithet inermis , meaning « unarmed » — which clearly distinguishes it from most other acaenas.
In its natural habitat, its flowering extends from December to February (austral summer). In cultivation under our latitudes, it blooms in June-July.
In the garden, its dark and evergreen foliage makes a striking contrast when associated with plants with silver or light green foliage, on rock gardens or between slabs.