Discaria toumatou, matagouri or wild irishman is endemic to the North and South Islands. In the North Island known from near Waiuku south to the southern Wairarapa and Wellington coastline, but is very uncommon in the North Island. In the South Island mainly east of the main divide, appearing to avoid areas of high rainfall.  Rather variable, and some North Island sand dune forms are entirely prostrate, forming trailing shrubs. An excellent hedge plant, with the added bonus that this species fixes atmospheric nitrogen, making it available for other plants.
Not threatened for most of its range, but however, very uncommon and under threat throughout the North Island, where it is now known from very few sites and viable populations. A spiny shrub or tree reaching up to 5m tall and found in dry riverbeds, open rocky places and sand dunes from the coast to subalpine regions.  The thorns are vicious.  It needs a dry sunny site but makes a wonderful contrasting plant or home security system.