recent estimates suggest the myrtaceae include approximately 5,950 species in about 132 genera. the family has a wide distribution in tropical and warm-temperate regions of the world, and is common in many of the world's biodiversity hotspots. genera with capsular fruits such as "eucalyptus", "corymbia", "angophora", "leptospermum", and "melaleuca" are absent from the americas, apart from "metrosideros" in chile and argentina. genera with fleshy fruits have their greatest concentrations in eastern australia and malesia (the australasia ecozone) and the neotropics. "eucalyptus" is a dominant, nearly ubiquitous genus in the more mesic parts of australia and extends north sporadically to the philippines. "eucalyptus regnans" is the tallest flowering plant in the world. other important australian genera are "callistemon" (bottlebrushes), "syzygium", and "melaleuca" (paperbarks). species of the genus "osbornia", native to australasia, are mangroves. "eugenia", "myrcia", and "calyptranthes" are among the larger genera in the neotropics.