This article was published in The Fringe, December 2014
In addition to the several species of Cyathodes, Leucopogon and Leptecophylla here is yet another species called mingimingi, one of the many twiggy Coprosma species that are called mingimingi, just to keep us all confused.
Coprosma propinqua is a three to six metre shrub, found widely throughout New Zealand, although absent from a number of significant areas including parts of Canterbury and Northland, Taranaki and the Waitakere Ranges. There is no obvious reason why it should not be in those areas as it is one of the toughest species of Coprosma and can be found in a wide range of habitats from the coast to subalpine habitats, including wetlands.
The divaricating form of mingimingi has a wide-angled and rigid branching habit creating an impenetrable thicket which resists browsing animals, particularly toothless herbivores. This form of mingimingi exemplifies the theory that New Zealand's divaricating shrubs evolved because of the browsing by moa. Apart from the springy, resistant branch network, the foliage is small, tough and definitely unpalatable. The flowers are typical of Coprosma species, almost invisible, but if you check outside throughout spring and early summer, there is bound to be a Coprosma in flower near you, with male and female flowers on separate plants. But it won't be a naturally growing Coprosma propinqua if you live in the wider Waitakere region.
As a previous article related, the native mistletoe, Ileostylus micranthus, has a limited range of hosts that it will live on, and Coprosma propinqua is one of them. So the Waitakere mistletoe plants are almost exclusively confined to totara trees where they flourish high above the canopy where they are seldom seen. With more Coprosma propinqua there is a chance the mistletoe could be found in your back yard. It is certainly to be found on Coprosma propinqua on the South Kaipara peninsula, the nearest population to the Waitakeres, and along the roadside at Miranda.
Coprosma propinqua frequently hybridises with the forest dwelling Coprosma lucida with the resulting progeny being named Coprosma x cunninghamii and it can be very fertile producing additional hybrid forms.
There is a quite different looking plant on the Chatham Islands which is known as Coprosma propinqua var. martinii which has evolved into two distinct forms. The mounding wiry form grows on sand dunes around the coastline, while inland swamp forms have a very upright, vertical growth habit.
In the nursery there are Coprosma propinqua plants from around the country and it is a clear demonstration of the need to practice eco-sourcing, as each area has quite a different look from all the others. As it does not occur naturally in the Waitakeres you are best advised to choose the eco-sourced type found nearest to where you live.