Metrosideros umbellata, Southern rata or ironwood is endemic to the North, South, Stewart and Auckland Islands. In the North Island it is present locally from Te Paki south to Mt Pirongia, the northern Kaimai Ranges (Ngatamahinerua) and Mt Manuoha (Te Urewera National Park). In the South Island from Durville Island south and to Fiordland, with a mainly westerly distribution, most of Canterbury and northern Otago, but absent from Marlborough. Also common on Stewart and the Auckland Islands. It is not threatened, but however, rather uncommon in the North Island, and at some sites it is locally threatened by possum browse.  North Island plants are genetically distinct from South Island plants but the differences cannot be matched to morphology. All recent southern rata collections made from the Tararua Ranges are the hybrid M. robusta x M. umbellata. A few photographs taken in the 1930s from the Francis Ridge, Southern Tararua Ranges may have been genuine M. umbellata but the species cannot be found there now. Other northern Tararua records of M. umbellata appear to be based on M. robusta. It is a beautiful, very slow growing specimen tree which should be more widely planted in locations where conditions are suitable, forms a dense shrub which grows to small, very slow growing tree 3 - 6m, sometimes up to 18m high. It is usually found in lowland to mountain regions and occassionally in subalpine forest and scrubland from sealevel to 1060m asl. It produces blood red flowers from November to March, but trees can take many years before they will flower. It will grow in most well drained soils and once established will tolerate dryness (water during dry weather until established). Frost hardy.