Discaria toumatou
Discaria toumatou, commonly known as matagouri (also called wild Irishman), is a spiny, nitrogen-fixing shrub endemic to New Zealand. It forms dense thickets on river terraces, dry hillsides and tussock grasslands, especially in the eastern South Island. Small white, fragrant flowers appear in spring, followed by capsules with shiny black seeds. Matagouri provides cover for native fauna and plays a key role in dryland restoration. native shrubs
Image credit: Matagouri (Discaria toumatou). Wikipedia
| Scientific Name | Discaria toumatou |
|---|---|
| Height | 1–3 m (occasionally to 4 m) |
| Spread | 1–3 m, forms thickets |
| Water Needs | Low once established; drought-tolerant |
| Light | Full sun to light shade |
| Frost Tolerance | High; suited to cold inland climates |
| Salt Tolerance | Low to moderate (not strongly coastal) |
| Growth Rate | Moderate |
| Lifespan | Long-lived shrub |
Best in temperate regions with low to moderate rainfall and free-draining soils. Naturally common east of the Southern Alps; tolerates wind, cold, and summer dryness.
| City | Climate Suitability |
|---|---|
| Whangārei | Moderate |
| Auckland | Moderate |
| Hamilton | Ideal |
| Tauranga | Ideal |
| Rotorua | Ideal |
| Gisborne | Ideal |
| New Plymouth | Ideal |
| Napier | Ideal |
| Whanganui | Ideal |
| Palmerston North | Ideal |
| Wellington | Ideal |
| Nelson | Ideal |
| Christchurch | Ideal |
| Dunedin | Ideal |
| Invercargill | Ideal |
Prefers free-draining, low to moderately fertile soils:
Requires good light for dense growth:
Drought-tolerant after establishment:
Prune cautiously due to thorns. Remove dead or crossing wood and keep paths clear. For hedges, clip lightly to maintain a dense face; avoid hard pruning into very old wood.
Plant in autumn or spring; avoid waterlogged conditions.
Endemic to New Zealand’s drier regions, especially eastern South Island. Matagouri thickets are characteristic of river terraces and tussock grasslands and provide important habitat structure within these ecosystems.
For wildlife value, group several plants to form a protective thicket and underplant with native grasses adapted to dry conditions.
These dryland natives share similar exposure and low‑water tolerance, creating resilient, wildlife‑friendly shrublands.
Learn more about the cultural significance of native plants in Cultural Plants.
Discaria toumatou is a densely branched, spiny shrub with zig‑zagging shoots and stout thorns at the nodes. Small, glossy leaves may be sparse on exposed plants. Fragrant white flowers appear in spring on short spurs; fruits are small capsules that release shiny black seeds. Roots host nitrogen‑fixing symbionts, allowing success on nutrient‑poor, stony soils.
Dry river terraces, shingle fans, outwash plains, and open hillsides, especially east of the Southern Alps, and locally in drier North Island sites. Prefers free‑draining, often rocky substrates in full sun with cold winters and summer drought.
As a nitrogen fixer, matagouri enriches poor soils and facilitates succession. Dense, thorny architecture provides refuge and nesting sites for small birds and lizards in open country. Flowers support pollinators; seeds typically fall near parents or are moved short distances by gravity and animals.
Foundation species in dryland shrublands, contributing to soil building, shelter, and biodiversity in otherwise harsh environments. Thickets stabilise stony ground and protect palatable species from browsing.
Water regularly only during establishment; thereafter minimal irrigation is needed. Mulch lightly with gravel or coarse organic matter in the first year to suppress weeds. Avoid rich fertilisers which reduce drought hardiness and encourage soft, pest‑prone growth.
Minimal inputs required. Prune lightly after flowering to shape and keep access clear; avoid severe cuts into old wood. Wear protective clothing when working around plants. Replace plants lost to extreme events to maintain continuous shelter.
Superb in dryland gardens, farm shelter on stony ground, and native restoration of braided river terraces. Combine with Olearia, Coprosma, and tussock grasses for authentic dryland assemblages.
Widespread but locally reduced by land clearance and browsing. Retain and connect remnant shrublands, manage grazing pressure, and use eco‑sourced plants to restore dryland ecosystems.
This plant has cultural associations in Aotearoa and is valued in restoration and gardens for ecological services; use eco‑sourced stock near natural areas.
Matagouri was recognized by Māori as an important component of dryland ecosystems and was used traditionally for making implements and tools from its hard wood, while the plant's formidable spines provided natural protection and were sometimes used defensively around settlements. The species was also valued for its medicinal properties, with various plant parts used to treat ailments, and its presence indicated specific environmental conditions in traditional ecological knowledge. The name 'matagouri' itself reflects the plant's characteristic spiny nature, and it remains culturally significant as an indicator of New Zealand's distinctive dryland environments.
