Eucalyptus
is a diverse genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of flowering

Flowering plant

The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

 tree

Tree

A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

s (and a few shrubs) in the myrtle family, Myrtaceae

Myrtaceae

The Myrtaceae or Myrtle family are a family of dicotyledon plants, placed within the order Myrtales. Myrtle, clove, guava, feijoa, allspice, and eucalyptus belong here. All species are woody, with essential oils, and flower parts in multiples of four or five...

. Members of the genus dominate the tree flora of Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. There are more than 700 species of Eucalyptus, mostly native to Australia, and a very small number are found in adjacent areas

Trans Fly savanna and grasslands

The Trans Fly savanna and grasslands are a lowland ecoregion on the south coast of the island of New Guinea in both the Indonesian and Papua New Guinean sides of the island...

 of New Guinea

New Guinea

New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...

 and Indonesia

Indonesia

Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

 and one, Eucalyptus deglupta

Eucalyptus deglupta

Eucalyptus deglupta is a tall tree, commonly known as the Rainbow Eucalyptus, the Mindanao Gum, or the Rainbow Gum. It is the only Eucalyptus species found naturally in the Northern Hemisphere. Its natural distribution spans New Britain, New Guinea, Ceram, Sulawesi and Mindanao.The unique...

, ranges north to the Philippines

Philippines

The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

. Only 15 species occur outside Australia, and only 9 do not occur in Australia.