Myrsine

Narrow small trees and human-sized shrubs are two of the most desirable growth forms for gardens – for obvious reasons. This genus provides us with some fine garden species that fit both those categories, and as a result are deserving of greater attention than they currently command.

Most notable amongst these are the two small trees, Myrsine divaricata and M. oliveri, and the northern shrub, Myrsine aquilonia (which is one of the best introductions into horticulture of recent years). A Chatham Island species, Myrsine coxii, also looks to be a good shrub for cooler areas, with a compact, upright growth habit and attractively coloured foliage. The comparatively large-leaved toro (Myrsine salicina) is a worthwhile small tree for shaded conditions in reasonably moist parts of the country, while on the other end of the spectrum, the creeping Myrsine nummularia is an interesting and beautiful plant for cold, high-altitude gardens.

The wind-sculpted shrub pictured above, Myrsine argentea, is one of three relatively recently-identified species to have been described from a group of geographically distinct entities formerly placed within a broad circumscription of Myrsine divaricata – including M. aquilonia, which is primarily associated with the Poor Knights Islands, and M. umbricola, an inhabitant of cloud forests in the Tararua Ranges. Myrsine is a widespread genus, found in many parts of the globe. New Zealand’s eleven species of Myrsine are all confined to our shores.

The columnar form of Myrsine divaricata is similar to that of another small native tree, Pittosporum obcordatum, with one significant difference – the distinctive weeping habit of the branches, that (in my opinion) gives them the character of falling water. The sense of movement evoked by this eccentric branching arrangement furnishes mature specimens of weeping matipo with a pronounced elegance.

The species grows naturally in a wide range of habitats, from lowland forest to subalpine scrub. Within gardens, it should ideally be given an open to semi-shaded aspect, with reasonably rich soil (similar to the kinds of soils found within the riverine and lowlying ecologies in which the species achieves its full potential).

Selecting locally-appropriate forms is of considerable importance for this species, especially for those wanting to grow M. divaricata in northern parts of the North Island.

M. divaricata is recognised (within Eagle’s Complete Trees and Shrubs of New Zealand, 2006¹) as constituting two distinct forms, one of which occurs throughout most of the country (southwards of the Bay of Islands, although less common in the north), and another northern form (which is found in coastal forest of Northland and Auckland). We regularly plant material of the latter form, that has endured towards the back of the dunes of Pakiri Beach, presumably as remnants of former secondary dune forest.

The photograph below (on the right) is from an extraordinary area of remnant forest at Paengaroa, near Taihape, where a proliferation of divaricate tree and shrub species grow (many of national significance). The weeping matipo at the centre of the image, which exceeded 5m in height, demonstrates its extreme columnar form (the tree was less than 1m in diameter).