''Agathis orbicula'' (Sarawak kauri) is a

coniferous Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All extant ...

tree native to the island of

Borneo Borneo (; id, Kalimantan) is the third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, and eas ...

. It is found scattered throughout

tropical rainforest Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as ''lowland equatori ...

s and

Kerangas forest The Sundaland heath forest, also known as ''Kerangas'' forest, is a type of tropical moist forest found on the island of Borneo, which is divided between Brunei, Indonesia, and Malaysia, as well as on the Indonesian islands of Belitung and Bang ...

s. It is commonly found on hills and plateaus. The species is facing a high risk of extinction due to its scattered distribution and the decline in quality of its habitat.

Description

''Agathis orbicula'' is a medium-sized tree of up to . Like all ''Agathis'', Sarawak Kauri is generally possessed of a large, straight trunk. The trunk is usually branchless until close to the top where branches are retained which form a globular crown. The leaves range in shape from ovangular to circular, and are glaucous on their underside. The leaves are roughly two by three centimetres; juvenile leaves are much larger by comparison and are roughly twice the size of adult leaves. It can be inferred that the tree is similar in its appearance to other large trees of the genus, particularly ''

Agathis borneensis ''Agathis borneensis'', also known as Borneo kauri, is a species of conifer in the family Araucariaceae. Description The Borneo kauri grows to a maximum height of 50 metres. It has a long narrow cone and dark green leaves. The closest relative o ...

''. This is because it is likely ''A. orbicula'' was mistaken for ''A. borneensis''.

Cones

The cones that the tree produces are approximately seven by five centimetres and display imbrication whilst the pollen cones are generally twelve by five millimetres, being quite small and having a bumpy texture due to the exposed microsporophylls. The cones are among the smallest in the genus ''Agathis'' when compared to the significantly larger pollen cones of other species such as ''

Agathis robusta ''Agathis robusta'' (syn. ''A. palmerstonii''), the Queensland kauri (pine) or smooth-barked kauri, is a coniferous tree in the family Araucariaceae. (Although sometimes called a pine, it is not a true pine, and has leaves, not needles.) It has a ...

''; its cones are in the millimetre range making them quite small.

Bark

The bark is described as being a deep brown and flaking off of the tree in irregular pieces and plates; it is also smooth and shiny. The underside of the bark is a reddish-brown colour with a granular texture and accompanied by a yellow resin produced by the sap of the tree.

Timber

The wood of the Sarawak Kauri is generally particularly straight-grained, and the colour of the timber beneath can range from a straw colour to reddish brown. It produces an attractive timber that is easily worked. However, due to an extreme scarcity and a loss of habitat the tree does not seem to be in use or ever have been used for commercial purposes.

References

External links

Gymnosperm Database: ''Agathis''
orbicula Endemic flora of Borneo Trees of Borneo Taxa named by David John de Laubenfels {{conifer-stub