Metrosideros in cultivation: Ra¯ta¯ and other species The second of a two-part series Murray Dawson1, Jack Hobbs2, Graeme Platt3 and Jim Rumbal4 Part One of this series provided an introduction to Metrosideros Jim Rumbal has uncovered of Jim Rumbals’) may have given a species and cultivars and traced some additional information on plant to his parents who had a beach cultivar origins for two species the po¯hutukawa plantings on the bach at Ohope at that time. It may – M. excelsaa (po¯hutukawa or Waitara River bank, Taranaki. As have been this plant that gave rise to New Zealand Christmas tree) and documented in Part One, selections the cultivar name. from these early plantings were M. kermadecensis (the Kermadec M. excelsaa ‘Exotica’: made by the late Felix Jury and po¯hutukawa). for completeness we should mention gave rise to M. excelsaa ‘Fire M. excelsa ‘Exotica’, an early This second article updates Mountain’ and M. excelsaa ‘Scarlet and illegitimate name “someone information on po¯hutukawa and traces Pimpernel’. Blair Hortor, a long- has put on the reverse form [of cultivar origins for the remaining retired groundsman and gardener M. excelsaa ‘Variegata’]” (Davies, species – the ra¯ta¯ trees and vines and of the former Waitara Borough 1968). This selection was not widely cultivars of non-New Zealand species. Council (now the New Plymouth offered under this name. Other District Council), clearly recalls reverse-variegated po¯hutukawa that these early plantings came include M. excelsa ‘Centennial’ and Po¯hutukawa updates from Duncan & Davies nursery M. excelsaa ‘Upper Hutt’. In Part One we mentioned and not from a Palmerston North naturalisations of M. excelsaa and Nursery as suggested in Part One. M. excelsaa ‘Mini Christmas’: M. kermadecensiss in other countries. According to Blair (pers. comm.), all since Part One of this article was Both species are also on Norfolk of the plantings in Waitara during published, Murray Dawson has Island, where M. excelsaa may be his long tenure came from Duncan uncovered Australian records of a starting to naturalise (de Lange et al., & Davies nursery. Some of these cultivar named M. ‘Mini Christmas’ 2005) and M. kermadecensiss has have vibrant orange-scarlet fl owers, (and M. ‘Mini Xmas’). This low naturalised (Green, 1994). Graeme as exemplifi ed by M. excelsaa ‘Fire growing cultivar is said to attain 1 m Platt has seen M. kermadecensiss well Mountain’. Jim Rumbal is of the tall (Curia Plants online catalogue, established at Ball Bay, Norfolk Island, opinion that orangey fl ower colours 2010) and is almost certainly a where Green (1994) also recorded it. may possibly have arisen through selection of M. excelsa. hybridisation between the usual red- M. excelsa ‘Octopussy’: The expedition to date the fl owered M. excelsaa and the yellow- another new po¯hutukawa cultivar po¯hutukawa growing at La Coruña in fl owered M. excelsaa ‘Aurea’. Spain has been postponed from late has come to light. This cultivar, 2010 to probably mid 2011 (Jonathan We can now confi rm that the named M. excelsaa ‘Octopussy’, has Palmer, pers. comm.). We await the variegated selection M. excelsa a distinctive weeping to spreading dating results from the forthcoming ‘Ohope’ was named after Ohope growth habit. It arose as an open tree ring counts with interest. Beach near Whakatane. This is pollinated seedling at the Naturally possibly another selection made Native NZ Plants Auckland nursery Since publication of the fi rst part of by Duncan & Davies nursery. Jim in 2004. Although the original this article, Lawrie Metcalf informs us Rumbal has been assessing it for plant died, propagation material is that the mature amenity trees of the many years, and considers the thin maintained through cuttings. It is yellow-fl owered M. excelsaa ‘Aurea’ white variegated margin to be quite estimated that this cultivar will grow growing at Sumner, Christchurch, attractive although the selection to 1.5–3 m tall and some plants were planted by the late Maurice John is not particularly vigorous. Only a are also being sold as standards Barnett (Superintendent of Parks and few were propagated at Duncan & (Esmé Dean, pers. comm.). Reserves, then Director of Botanic Davies nursery. Michael Sheerin New Zealand Plant Variety Rights Gardens, Parks and Reserves, (an employee of Duncan & Davies has been applied for (Serra Kilduff, Christchurch) probably in the 1950s. nursery and former work colleague pers. comm.). Landcare Research, PO Box 40, Lincoln 7640, New Zealand; [email protected] 2 Auckland Regional Botanic Gardens, 102 Hill Road, Manurewa, Auckland, New Zealand; [email protected] 3 New Zealand Botanical Institute, PO Box 302084, North Harbour, Auckland, New Zealand 4 Matarikoriko Road, Waitara, New Zealand 10 New Zealand Garden Journal, 2010, Vol. 13(2) M. excelsa ‘White Caps’: north and John Dawson named it ground in sunny sites, often where Graeme Platt recently selected and after him when formally describing it a forest has been destroyed by fi re. named a white-fl owered po¯hutukawa. as a new species (Dawson, 1985). Northern ra¯ta¯ that establishes on He discovered it at Piha Beach, M. bartlettiii is probably a specialised the ground may not become as tall west of Auckland City, during late epiphyte under most circumstances as those that are initially epiphytic December 2009. The parent tree was in the wild but eventually grows into (John Dawson, pers. comm.). The found planted in a reserve where it is an independent tree (John Dawson, leaves of M. robustaa are up to 5 cm thriving. It is a vigorous and healthy pers. comm.). It has distinctive or more long and crimson fl owers tree regardless of its unusual white whitish, tissue-paper like bark and appear mainly from November to fl owers (Fig. 1A–B). The aerial roots dark green leaves up to 5 cm long in January (Fig. 3A–B). This species running down the trunk have white a dense canopy, with masses of small occurs naturally on the Three Kings tips (instead of the usual reddish- white fl owers in October to November. Islands, is scattered throughout the brown colour) that mirror the lack of North Island where it used to be The conservation status of M. bartlettii pigmentation of its fl owers. M. excelsa more widespread, and is abundant is ‘Nationally Critical’ as it is only ‘White Caps’ is named after its fl ower in the South Island in North-West known from 29 adult plants in the wild colour and the sea wind blowing Nelson and Westland south to near (de Lange et al., 2010; New Zealand the tops of waves into whitecaps. It Greymouth (Allan, 1961; Simpson, Plant Conservation Network website, is currently under propagation with 2005). 2010). the purpose of introducing it into wider cultivation. Denis Hughes of Although its natural habitat is swampy Blue Mountain Nurseries was the ground, M. bartlettiii also grows well fi rst person to collect cuttings off the in average garden conditions in parent tree for commercial production. Auckland (Fig. 2A–B; Hobbs, 1992; Anon., 2001b). Graeme Platt believes that it has considerable potential as a street tree and that it may be more cold tolerant than most M. excelsa selections. Considering its rarity in the wild, this species should be grown more widely and is available from specialist native plant nurseries (e.g., Gaddum, 1997, 1999a, 1999b, 2001). A A A B B Fig. 3 Metrosideros robusta. A, botanical Fig. 1 Metrosideros excelsa ‘White Caps’. illustration (then as M. fl orida) in Curtis’s A, tree in fl ower. B, close-up of fl owers. B Botanical Magazine, London, Vol. 75 Photos: Graeme Platt. Fig. 2 Metrosideros bartlettii. A, tree in (= Ser. 3, Vol. 5): Tab. 4471, 1849. Image fl ower. Photo: Jack Hobbs. B, close-up of courtesy Missouri Botanical Garden, www. fl owers. Photo: Naturally Native NZ Plants. botanicus.org. B, plant in fl ower. Photo: Ra¯ta¯ trees ©Paul Ashford, www.NZPlantPics.com. Metrosideross robusta Metrosideross bartlettii M. robustaa is commonly available (northern ra¯ta¯) (Bartlett’s ra¯ta¯) through the nursery trade. Although In relatively undisturbed forest, Incredibly, this large tree (which not as wind hardy as M. excelsa, northern ra¯ta¯ is a specialised epiphyte can attain 25 m in height) escaped M. robustaa is more cold tolerant and can become a tall upright tree to notice until 1977 when the late John (Bannister, 1990) and makes an 30 m. Like other specialised epiphytic Bartlett discovered it. Bartlett found excellent specimen tree with an Metrosideros, it can also grow on the it at Radar Bush, Te Paki, in the far upright growth habit for an exposed New Zealand Garden Journal, 2010, Vol. 13(2) 11 site. When fully mature, M. robusta Metrosideross umbellata Stockton Plateau in an area called the is a large tree in the wild, but it (southern ra¯ta¯) ‘burning mine’, an historic abandoned grows slowly and can be managed This shrub or small tree grows to coal mine that has been on fi re since in cultivation where it takes several 15 m or more and like other ra¯ta¯ trees the early 1900s. The original plant years to fl ower when raised from can start life as an epiphyte (John was noticed because of its round seed. A few selections have been Dawson, pers. comm.). It has narrow squat shape and very short internodal made from this species: pointed leaves to 6 cm or more long growth. The leaves are slightly smaller and masses of small, usually red, than is typical for the species and M. robusta ‘Kawa Copper’: a new fl owers occurring sporadically from it produces bright crimson fl owers. cultivar that arose in 2001 from a November to March.