Metrosideros umbellata


Metrosideros umbellata, the southern rata, is a tree endemic to New Zealand. It grows up to or more tall with a trunk up to or more in diameter. It produces masses of red flowers in summer. Unlike its relative, northern rata, this species rarely grows as an epiphyte.

Description

The flowers of southern rata are scarlet, with stamens about long. White or yellow flowers are also known. Flowering usually occurs between December and February, but this depends on local conditions. Leaves are from to long, and are sharply pointed. The wood is hard, dense, and very strong. The bark is rough and flaky and provides an ideal stratum for the roots of epiphytic plants such as Astelia species and Freycinetia banksii. Southern rata is a major source of honey on the West Coast of the South Island. Kaka, tui, and bellbirds visit rata to take advantage of the abundant nectar.

Distribution

It prefers cooler regions with high rainfall and is particularly common along the west coast of the South Island where its nectar is the main source of a locally produced rata honey. Southern rata is the most widespread of the New Zealand tree rata species. It is locally present in the North Island from latitude 36° southwards, is more common in western parts of the South Island but absent from much of the east, and is common on Stewart Island and in the Auckland Islands, where it reaches its southern limit at just over 50°S.

Conservation

Although southern rata is not regarded as threatened, it is rather uncommon in the North Island, and in certain areas it is threatened by possum browse. In the Tararua range, southern rata populations appear to have been replaced by a population consisting of hybrids between northern and southern rata.
Project Crimson is a charitable trust that promotes conservation of rata as well as the related pohutukawa.

Cultivation

Southern rata is a beautiful specimen tree, but growth can be slow unless it is grown in ideal conditions with moist soil. It is easily grown from fresh seed. While it is possible to grow the tree from softwood or semi-hardwood cuttings, these often prove reluctant to strike roots. It is ideal for coastal environments because it has a good resistance to wind and salt.
At least 16 cultivars of southern rata have been released. There are also known cultivars of hybrids between southern rata and pohutukawa, and between northern rata and southern rata. Known cultivars include:
Cultivar nameYear introducedFlower colourIntroduced byNotes
M. umbellata ‘Alba’mid-1980sWhite/creamDenis HughesLeaves are a paler lemon-green then standard plants. Sourced from Soaker Hill in the Catlins, South Otago.
M. umbellata ‘Christmas Dream’Late 1970sRedDenis HughesSourced from Lake Manapouri.
M. umbellata ‘Denniston Yellow’1995Sulphur YellowDeane KeirSourced from the Denniston Plateau.
M. umbellata ‘Fireball’1993Bright crimsonDeane KeirSourced from the Stockton Plateau at a place called Burning Mine.
M. umbellata ‘Firecracker’1995Deep redJeff ElliottSourced from Whanganui Inlet, North-West Nelson.
M. umbellata ‘Gold Beacon’-Sulphur YellowLes ClevelandSourced from the Otira Gorge.
M. umbellata ‘Gold Nugget’1992RedJoe CartmanGolden new leaves with thin red leaf margins. Sourced from side-shoot of M. umbellata ‘Harlequin’. Also sold as M. umbellata ‘Lownug’.
M. umbellata ‘Harlequin’md-1980sRedJoe CartmanVariegated cultivar with yellow leaf margins. Sourced from Nugget Point.
M. umbellata ‘Kaka’late-1990sPinkDenis HughesSourced from Kaka Point, Otago.
M. umbellata ‘Moonlight’2001RedPattersons NurseriesReverse variegated cultivar. Sourced from side-shoot of M. umbellata ‘Gold Nugget’. Also sold as M. umbellata ‘Lowmoo’.
M. umbellata ‘Mt Augustus’Late-1970sRedLouise SalmondSourced from the Stockton Plateau at a place called Mt Augustus.
M. umbellata ‘Red Tips’Mid-1990sRedLes ClevelandNew leaves have a red tip. Sourced from an island in Lake Wanaka.
M. umbellata ‘St Nicholas’Late 1970sRedDenis HughesSourced from Lake Manapouri.
M. umbellata ‘Scarlet Beacon’2002RedLes Cleveland-
M. umbellata ‘Silver Beacon’Mid-1990sRedLes ClevelandNew leaves have a silvery tip. Sourced from an island in Lake Wanaka.
M. umbellata ‘Sparrow’s Hybrid’1994RedMr SparrowSourced from the banks of the Avon River in Christchurch, between Madras and Manchester Streets. Source material provided by Mr Sparrow, a customer of the nursery. Despite the name, this cultivar is not a hybrid.
¤ Metrosideros ‘Cleveland Red’late-1990sScarletLes ClevelandDeliberate interspecific hybrid.
¤ Metrosideros ‘Maungapiko’1985Bright crimsonGraeme PlattSourced from Maungapiko Track, Great Barrier Island.
¤ Metrosideros ‘Rustic Beauty’1985-Les ClevelandDeliberate interspecific hybrid.
∞ Metrosideros ‘Sentinel Flame’2007Bright redGraeme Platt / Vibrant Earth nurserySourced from either Great Barrier Island or North-West Nelson.

∞ Hybrid of southern rata and northern rata

¤ Hybrid of southern rata and pohutukawa