Flora Indonesia

The flora in Indonesia consists of many unique varieties of tropical plants. Blessed with a tropical climate and around 18,000 islands, Indonesia is a nation with the second largest biodiversity in the world. The flora of Indonesia reflects an intermingling of Asian, Australian and the native species. This is due to the geography of Indonesia, located between two continents. The archipelago consists of a variety of regions from the tropical rain forests of the northern lowlands and the seasonal forests of the southern lowlands through the hill and mountain vegetation, to sub-alpine shrub vegetation. Having the second longest shoreline in the world, Indonesia also has many regions of swamps and coastal vegetation. Combined together, these all give rise to a huge vegetational biodiversity.

There are about 28,000 species of flowering plants in Indonesia, consisting 2,500 different kinds of orchids, 6,000 traditional medicinal plants used as jamu, 122 species of bamboo, over 350 species of rattan and 400 species of Dipterocarpus, including ebony, sandalwood and teakwood. Indonesia is also home to some unusual species such as carnivorous plants. One exceptional species is known as Rafflesia arnoldi, named after Sir Thomas Stamford Raffles and Dr. Arnold, who discovered the flower in the depths of Bengkulu, southwest Sumatra. This parasitic plant has a large flower, does not produce leaves and grow on a certain liana on the rain forest floor. Another unusual plant is Amorphophallus titanum from Sumatra. Numerous species of insect trapping pitcher plants can also be found in Borneo, Sumatra, and other islands of the Indonesian archipelago.

According to the Conservation International, there are two biodiversity hotspots in Indonesia: Wallacea and Sundaland. The provinces of West Papua and Papua are also extremely biodiverse. Lorentz National Park, located in the province of Papua, was declared a World Heritage Site in 1999 by UNESCO.

Wallacea represents the biogeographical transitional zone between the Sundaland to the west and the Australasian zone to the east. This zone covers of about 338 494 km² land area in total, divided in multiple small islands. Due to its distinct and varied geography this region contains many endemic and unique species of flora and fauna and has been divided into a number of distinct ecoregions; the mountain and lowland areas of Sulawesi, North Maluku, Buru and Seram in Maluku, the Lesser Sunda Islands (with Sumba a distinct ecoregion in its own right), Timor, and the islands in the Banda Sea.

Sundaland

Sundaland, which is located on the west part of the Indonesian archipelago, holds about 25,000 different species of plants. 15,000 of them are endemic to this region and cannot be found anywhere else. Scyphostegiaceae is a plant family represented by a single species, Scyphostegia borneensis, which is endemic to Borneo. Another 155 species of Dipterocarpus are also endemic to this island. Borneo also has more than 2,000 species of orchids. The forests in Sumatra include more than 100 species of Dipterocarpus, nearly a dozen of them are endemic to this island. The island Java has about 270 endemic orchid species.

At least 117 plant genera are endemic in this biodiversity hotspot. 59 of them are found in Borneo and 17 in Sumatra. Unique plants from this region are similar to ones from the Asian continent, mentioning Rafflesia arnoldii, the pitcher plants and Javanese Edelweiss (Anaphalis javanica) as examples.

Wallacea

It is estimated, that there are about 10,000 species of plants in this biodiversity hotspot region. The island of Sulawesi has about 500 endemic plant species. The islands of Moluccas have about 300 endemic plant species and the Lesser Sunda Islands consist of at least 120 endemic plant species. Little is known about the flora of this region. Three of these unique species, Agathis, Pterocarpus indicus, and Eucalyptus deglupta, are mentioned as examples.

West Papua and Papua

The flora of this region has somewhat the influence of the Australian continent. This region contain a continuous transect from snow cap mountains, lowland wetlands to tropical marine environment. This is the perfect place for such a huge number of diverse plant species. It has been estimated that Papua and west Papua may contain from 20,000 to 25,000 species of vascular plants. An astonishing 60-90% of them may be endemic to this region. This region has been poorly explored so the actual number of endemic species is unknown.