{{Short description|Species of flowering plant}} {{speciesbox |image = SmithMCollina.jpg |image_caption = |genus = Metrosideros |species = collina |authority = (J.R.Forst. & G.Forst.) A.Gray (1854) |synonyms= *''Leptospermum collinum'' <small>J.R.Forst. & G.Forst. (1776)</small> *''Nania collina'' <small>(J.R.Forst. & G.Forst.) Kuntze (1891)</small> |synonyms_ref = <ref name = powo>[https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:598184-1 ''Metrosideros collina'' (J.R.Forst. & G.Forst.) A.Gray]. ''Plants of the World Online''. Retrieved 28 May 2023.</ref> }}
'''''Metrosideros collina''''' is a species of flowering plant in the family Myrtaceae. It is a tree or shrub native to French Polynesia, the Cook Islands, and the Pitcairn Islands.<ref name = powo/>
==Taxonomy== [[Image:metrosideros collina.jpg|thumb|left|''M. collina'' var ''villosa'' in Royal Tasmanian Botanical Gardens, Hobart]] The species was first formally described by botanist Johann Reinhold Forster and his son Georg Forster in 1776. It was given the name ''Leptospermum collinum''.
''M. collina'' was formerly thought to have a larger range, extending to Vanuatu, Fiji, and the Samoan Islands. A phylogenetic study, published in 2015 by Pillon ''et al.'', found that ''M. collina'' comprised two genetically distinct groups, and the populations in Vanuatu, Fiji, and Samoa were recognized as a distinct species, ''M. vitiensis''.<ref name = Pillon>Pillon, Y., Lucas, E., Johansen, J. B., Sakishima, T., Hall, B., Geib, S. M., & Stacy, E. A. (2015). An Expanded Metrosideros (Myrtaceae) to Include Carpolepis and Tepualia Based on Nuclear Genes. ''Systematic Botany'', 40(3), 782–790. http://www.jstor.org/stable/24546499</ref>
==Habitat== In the Society Islands, ''Metrosideros collina'' is a common canopy tree in montane rain forests above {{convert|300|m}} elevation, and in cloud forests from {{convert|400|to|1000|m}} elevation, and on exposed ridges.<ref name = Society>{{WWF ecoregion|name=Society Islands tropical moist forests|id=oc0113}}</ref>
In the Marquesas Islands, ''Metrosideros collina'' is common on drier and more exposed montane forests, in cloud forests, and in shrub form in windswept mountaintop shrublands.<ref name = Marquesas>{{WWF ecoregion|name=Marquesas tropical moist forests|id=oc0108}}</ref>
On Rarotonga in the Cook Islands, ''Metrosideros collina'' is the dominant tree in cloud forests on the island's cloud-shrouded peaks and ridges above {{convert|400|m}} elevation. ''M. collina'' and associated trees, including ''Pterophylla samoensis, Elaeocarpus floridanus'', and ''Pittosporum rarotongense'', form a low forest canopy averaging eight meters tall. In wetter areas and at higher elevations ''Ascarina diffusa'' is often co-dominant or dominant in the canopy. ''M. collina'' is also found in lower-elevation rainforests dominated by ''Homalium acuminatum''.<ref name = Cook>{{WWF ecoregion|name=Cook Islands tropical moist forests|id=oc0103}}</ref>
''Metrosideros collina'' is a common canopy tree in higher-elevation interior forests on Pitcairn Island, with the trees ''Homalium mouo, Ficus prolixa, Pandanus tectorius'', and ''Thespesia populnea''.<ref name = Tuamotu>{{WWF ecoregion|name=Tuamotu tropical moist forests|id=oc0115}}</ref>
==Varieties== There are two accepted varieties:<ref name = powo/> *''Metrosideros collina'' var. ''collina'' – Society Islands *''Metrosideros collina'' var. ''villosa'' – Cook Islands, Marquesas Islands, Pitcairn Islands, Society Islands, Tuamotu, and Tubuai Islands.
==Cultivars== thumb|right|Cultivar 'Tahiti' Cultivars of ''Metrosideros collina'' are used as ornamental plants, for planting in tropical and subtropical climate gardens. Cultivars include: * 'Tahiti', grows to about {{convert|1|m}}, * 'Tahitian sunset', a mutated form of 'Tahiti' with variegated leaves<ref>{{cite patent|url=http://www.google.com/patents/US20080313783|country=US|title=''Metrosideros'' plant named "Tahitian Sunset" |number=20080313783 P1}}</ref>
==References== {{Reflist}}
{{Taxonbar|from=Q781752}}
collina Category:Flora of the Cook Islands Category:Flora of the Marquesas Islands Category:Flora of the Pitcairn Islands Category:Flora of the Society Islands Category:Flora of the Tuamotus Category:Flora of the Tubuai Islands Category:Garden plants of Australasia Category:Plants described in 1776 Category:Taxa named by Asa Gray