Australasian realm

Melanesia is a subregion of Oceania in the southwestern Pacific Ocean. It extends from New Guinea in the west to the Fiji Islands in the east, and includes the Arafura Sea. Melanesia borders Southeast Asia to the west, Polynesia to the east, Micronesia to the north and Australia to the south.

thumb|upright=1.25|Australia's concept of Australasia, which includes Australia, New Zealand and, in this case, Melanesia

one of the Earth's eight biogeographic realms

thumb|upright=1.6|Wallacea is the group of islands within the red area. The Max Carl Wilhelm Weber|Weber Line in blue has been used to separate Wallacea into a western part pertaining to [[Asia and an eastern part pertaining to Oceania.]] upright=1.6|thumb|The Sunda Shelf|Sunda and Sahul shelves. Wallacea is the area in between.

thumb|upright=1.2|Map 1: A very broad definition of Malesia includes both the World Geographical Scheme for Recording Plant Distributions's Malesia (green) and most of its Papuasia (orange). Malesia is a biogeographical region straddling the Equator and the boundaries of the Indomalayan and Australasian realms. It is a phytogeographical floristic region in the Paleotropical kingdom. It was first recognized as a distinct region in 1857 by Heinrich Zollinger, a Swiss botanist and explorer. The precise boundaries used to define Malesia vary. The broadly defined area used in Flora Malesiana consis

thumb|Papuasia as defined by the WGSRPD