Potentilla

Although our sole native species of Potentilla seems very different in character from its more famous cousins, a second look at this creeping groundcover readily identifies it as a member of the rose family. The bright yellow flowers have a simple form that resembles a pared-back rose, whilst the shape of the divided leaves is very similar to the foliage on roses.

Potentilla is a large genus of several hundred species (of herbs and shrubs), which is widespread in distribution (particularly in the Northern Hemisphere). Many varieties are grown for the beauty of their flowers (some within New Zealand), as well as their relatively tidy habit and strawberry-like foliage.

The leaves of Potentilla anserinoides create an elegant, bronze carpet over summer, within the damp situations in which this deciduous groundcover species is naturally found. Despite its attractive foliage, it has been almost completely absent from horticultural literature within New Zealand (the exception being a brief mention in Muriel Fisher’s ‘Gardening with New Zealand Plants, Shrubs & Trees’¹). This may be partially due to its deciduous nature; a characteristic that requires consideration when planting this species (by combining it with another groundcover that can take up the slack in winter).

Although its natural range starts just south of Auckland (in a range of habitats, especially on the margins of wetlands), it grows perfectly well within Auckland (where we have grown it for years in average garden conditions). It is best planted in moist soil with an open aspect, and may be combined with species such as Lobelia perpusilla to ensure consistent coverage of the ground.

I have viewed this species in the wild in several parts of the South Island, including on the margin of Lake Alexandrina (pictured below) and in swampy ground at the Glenmore Tarns (both of which lie within the Mackenzie Basin). The plants at Lake Alexandrina demonstrated its ability to endure within highly modified habitats; as it grows amongst exotic turfgrasses that would receive a fair amount of foot traffic.

Early botanists (notably Hooker and Cheeseman) did not consider Potentilla anserinoides to be a distinct species, deciding instead that it was a variety of the widespread P. anserina. However, in more recent times, it has been correctly recognised as endemic to New Zealand.