World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0000476915
Reproduction Date:

Title: Metrosideros  
Author: World Heritage Encyclopedia
Language: English
Subject: Metrosideros excelsa, Metrosideros elegans, Metrosideros polymorpha, Hyles wilsoni, Rata
Collection: Flora of New Caledonia, Metrosideros, Trees of Hawaii, Trees of New Zealand
Publisher: World Heritage Encyclopedia


Flowers and foliage of M. excelsa
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Myrtales
Family: Myrtaceae
Subfamily: Myrtoideae
Tribe: Metrosidereae
Genus: Metrosideros
Banks ex Gaertn.[1]

See list.

  • Agalmanthus (Endl.) Hombr. & Jacquinot
  • Ballardia Montrouz.
  • Carpolepis (J.W.Dawson) J.W.Dawson
  • Mearnsia Merr.
  • Microsideros Baum.-Bod. nom. inval.

Metrosideros [3] is a genus of approximately 50 trees, shrubs, and vines native to the islands of the Pacific Ocean, from the Philippines to New Zealand and including the Bonin Islands, Polynesia, and Melanesia, with an anomalous outlier in South Africa. Most of the tree forms are small, but some are exceptionally large, the New Zealand species in particular. The name derives from the Ancient Greek metra or "heartwood" and sideron or "iron". Perhaps the best-known species are the pōhutukawa (M. excelsa), northern rātā (M. robusta), and southern rātā (M. umbellata) of New Zealand, and ʻōhiʻa lehua, (M. polymorpha), from the Hawaiian Islands.


  • Distribution 1
  • Cultivation 2
  • Metrosideros species 3
  • References 4


New Caledonia has 21 species of Metrosideros, New Zealand has twelve, Hawaiʻi has five, and Papua has four. The remainder are scattered across small islands of the Pacific, with one outlier described from South Africa. Metrosideros seeds can disperse on the wind, which accounts for their wide distribution from a presumed origin in a greater New Zealand continent, which at the time of the breakup of Gondwana in the late Cretaceous, included New Caledonia. How the genus reached Hawaiʻi appears puzzling because the prevailing trade winds blow from the east. However high altitude wind patterns may have brought seeds north from the Marquesas Islands, which molecular evidence suggests as the origin of the Hawaiian species from a single colonising event (the Hawaiian M. polymorpha is similar to the widespread M. collina found in the Marquesas Islands, and was long classified as a subspecies of it). Considering that the group likely spread north and east from New Zealand, counter to prevailing ground-level winds, this is not surprising.


Metrosideros are often cultivated for their showy flowers, as street trees or in home gardens. The flowers are generally red, but some cultivars have orange, yellow or white flowers. Some names listed in horticultural catalogs and other publications, such as M. villosa and M. vitiensis, are actually the names of varieties or cultivars (usually of M. collina) rather than valid scientific species. The pōhutukawa of New Zealand has several cultivars grown in Australia, Hawaiʻi and California and it has been planted successfully in the north of Spain[4] and on the Scilly Isles off the south-west coast of Britain,[5] but the species is considered an invasive pest in parts of South Africa. Metrosideros kermadecensis is recently naturalised in Hawaiʻi, and has the potential to become a pest. In turn, various cultivars of M. collina and M. polymorpha are widely grown in New Zealand under various names. Metrosideros umbellata occurs naturally south of mainland New Zealand in the Auckland Islands at 50° South latitude, and is the hardiest member of the genus, and a few cultivated specimens are growing in Scotland.

Metrosideros species

There are approximately 50 species of Metrosideros, in three subgenera: Mearnsia, 24 or 25 species, trees, shrubs (some epiphytic) and vines, with red, pink, white, yellow or orange flowers; Metrosideros, 26 species, trees and shrubs, flowers mostly red, but some species have yellow or white flowers; and Carpolepis, 3 species of hemi-epiphytic rainforest trees from New Caledonia, all with bright yellow flowers.

Subgenus Metrosideros Phylogenetic Tree[6]

M. Umbellata/Southern rātā (New Zealand)

M. boninensis (Bonin Islands)

M. ochrantha (Fiji)

M. salomonensis (Solomon islands)

M. microphylla (New Caledonia)

M. cherrieri (New Caledonia)

M. engleriana (New Caledonia)

M. humboldtiana (New Caledonia)

M. punctata (New Caledonia)

M. nitida (New Caledonia)

M. oreomyrtus (New Caledonia)

M. collina var collina (Vanuatu)

M. Sp (Vanuatu)

M. collina var collina (Samoa)

M. gregoryi (Samoa)

M. fruticosa (Fiji)

M. collina var collina (Fiji)

M. excelsa/Pōhutukawa (New Zealand)

M. collina var collina (Rarotonga)

M. collina var vilosa (Tahiti)

M. kermadecensis/Kermadec pōhutukawa (Kermadec Islands)

M. nervulosa/Mountain Rose (Lord Howe Island)

M. sclerocarpa/Mountain Rose (Lord Howe Island)

M. macropus/Lehua mamo (Hawaiʻi)

M. polymorpha/ʻŌhiʻa lehua (Hawaiʻi)

M. rugosa/Lehua papa (Hawaiʻi)

M. tremuloides/Lehua ʻāhihi (Hawaiʻi)

M. waialealae/Kauai Bottlebrush (Hawaiʻi)

M. robusta/Northern rātā (New Zealand)

M. bartlettii/Bartlett's rātā (New Zealand)

Subgenus Mearnsia Phylogenetic Tree[7]

M. angustifolia (South Africa)

M. ovata (New Guinea)

M. ramiflora (New Guinea)

M. cordata (New Guinea)

M. whiteana (New Guinea)

M. salomonensis (Solomon Islands)

M. halconensis (Philippines)

M. albiflora (New Zealand)

M. diffusa (New Zealand)

M. colensoi (New Zealand)

M. carminea (New Zealand)

M. fulgens (New Zealand)

M. cacuminum (New Caledonia)

M. operculata (New Caledonia)

M. paniensis (New Caledonia)

M. rotundifolia (New Caledonia)

M. patens (New Caledonia)

M. perforata (New Zealand)

M. brevistylis (New Caledonia)

M. longipetiolata (New Caledonia)

M. dolichandra (New Caledonia)

M. porphyrea (New Caledonia)

M. whitakeri (New Caledonia)

M. parkinsonii (New Zealand)


  1. ^ Banks ex Gaertn."Metrosideros".  
  2. ^ "World Checklist of Selected Plant Families". 
  3. ^ Sunset Western Garden Book, 1995:606–607
  4. ^ "New Zealand Plants Overseas". 
  5. ^ Christmas tree, Pohutukawa
  6. ^ S. D. Wright; C. G. Yong; J. W. Dawson; D. J. Whittaker; R. C. Gardner (April 11, 2000). "Riding the ice age El Nino? Pacific biogeography and evolution of Metrosideros subg. Metrosideros (Myrtaceae) inferred from nuclear ribosomal DNA" (PDF). Proceedings of the National Academy of Sciences 97 (8): 4118–4123. Retrieved 18 February 2015. 
  • Simpson, P., 2005. Pōhutukawa & Rātā: New Zealand's Iron-Hearted Trees. Te Papa Press. 346 pp.
  • Wagner, W.L., D. R. Herbst, and S.H. Sohmer. 1999. Manual of the Flowering Plants of Hawaii. Revised edition. University of Hawaiʻi Press and Bishop Museum Press, Honolulu. 1919 pp.
  • Wright, S. D., C. G. Yong, S. R. Wichman, J. W. Dawson, and R. C. Gardner. (2001). Stepping stones to Hawaii: a trans-equatorial dispersal pathway for Metrosideros (Myrtaceae) inferred from nrDNA (ITS+ETS). J. Biogeography, 28(6): 769-774.
  • Wright, S. D., R. D. Gray, and R. C. Gardner. (2003). Energy and the rate of evolution: inferences from plant rDNA substitution rates in the Western Pacific. Evolution, 57(12): 2893–2898.
  • Wright, S.D.; C. G. Yong; J. W. Dawson; D. J. Whittaker; R. C. Gardner (2000-03-21). (Myrtaceae) inferred from nuclear ribosomal DNA"Metrosideros subg. Metrosideros"Riding the ice age El Niño? Pacific biogeography and evolution of (PDF). PNAS. Retrieved 2007-06-13. 
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.