Metrosideros /ˌmɛtrəˈsɪdərəs, -troʊ-/ is a genus of approximately 60 trees, shrubs, and vines mostly found in the Pacific region in the Myrtaceae family. 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 ( (Wikipedia)