Acaena microphylla

The Acaena microphylla, also known as the small-leafed burr, is a small, vigorous, light, original perennial ground cover plant with tiny bronze sorrel-like foliage that turns green and coppery as it matures. It is covered in summer with small greenish globular flowers followed by attractive dark pink spiky fruits in autumn. Delicate but not invasive, this effective ground cover can be used between paving stones, as a border highlight or as a substitute for a lawn in lightly trafficked areas. Very pleasant in a sunny rockery, this little plant thrives in well-drained soil, healthy in winter and not too dry in summer.  

Native to the meadows of New Zealand, this burr is one of the smallest in its genus. This perennial of the rose family forms a dense cushion measuring 30 cm (12in) wide, with pale green compound leaves finely divided into leaflets not exceeding 3 mm (1in) in diameter. Its foliage is evergreen in mild climates. Its leaves are carried by underground stems and roots, allowing it to spread over time. In June-July, small white to greenish flowers appear in small spheres. In autumn, countless curious fruits, globular and spiky but not prickly and of a lovely dark pink shade, stand out above the foliage and last several weeks until the end of summer. Fruits attach to animals' hair, promoting dispersion over long distances. 

The small-leafed burr is a plant that thrives in almost any type of soil in alpine climates, but it is generally much less demanding to grow than strictly mountain species. However, it does not tolerate very dry summers at all. Perfectly hardy, Acaena microphylla is highly appreciated in rockeries, as a border plant or as a ground cover at the base of bushes accompanied by small spring bulbs and colourful grasses such as Imperata cylindrica Red Baron. It also grows well in containers or pots, where it will easily spill over. Acaena can also be used on a green roof or living wall in cool climates when combined with small sedums, houseleeks, saxifrages or small grasses.