This has been a lovely and hardy perennial, in its third year for me, and survived this past winter nicely, whether one would call it a "groundcover", a "dwarf shrub", or, just a perennial -- it fills out into a nice hump about 6 to 8 inches high, neat and rounded, full of rather wiry little stems covered with small leaves and soon, small white flowers. I would like to recommend it for our supposedly milder climate in the Pacific NW or similar, not knowing where Parahebe is native to, and to suggest it for a rock garden with some sun available. The buds sparkle above the flowers like a wedding bouquet...
Additional info on this plant, from http://www.hebesoc.org ..."Parahebe catarractae grows beside streams, on cliffs and rocky places in lowland to mountain areas of North Island, South Island, and Stewart Island, New Zealand. A variable plant with several forms in cultivation"