Agathis

Agathis
Temporal range:
Paleocene to recent 64.67–0 Ma
Agathis australis New Zealand
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Gymnospermae
Division: Pinophyta
Class: Pinopsida
Order: Araucariales
Family: Araucariaceae
Genus: Agathis
Salisb. 1807
Type species
Agathis loranthifolia
Salisb. 1807
Distribution of Agathis species
Synonyms
  • Dammara (Rumph., 1741) Lam., 1786 ex Link, 1822
  • Salisburyodendron A.V.Bobrov & Melikyan

Agathis, commonly known as kauri or dammara, is a genus of evergreen coniferous trees, native to Australasia and Southeast Asia. It is one of three extant genera in the family Araucariaceae, alongside Wollemia and Araucaria (being more closely related to the former). Its leaves are much broader than most conifers. Kauri gum is commercially harvested from New Zealand kauri.

Description

Bark of Agathis robusta at Melbourne Royal Botanic Gardens (leaves belong to another plant)

Mature kauri trees have characteristically large trunks, with little or no branching below the crown. In contrast, young trees are normally conical in shape, forming a more rounded or irregularly shaped crown as they achieve maturity.

The bark is smooth and light grey to grey-brown, usually peeling into irregular flakes that become thicker on more mature trees. The branch structure is often horizontal or, when larger, ascending. The lowest branches often leave circular branch scars when they detach from the lower trunk.

The juvenile leaves in all species are larger than the adult, more or less acute, varying among the species from ovate to lanceolate. Adult leaves are opposite, elliptical to linear, very leathery and quite thick. Young leaves are often a coppery-red, contrasting markedly with the usually green or glaucous-green foliage of the previous season.

The male pollen cones appear usually only on larger trees after seed cones have appeared. The female seed cones usually develop on short lateral branchlets, maturing after two years. They are normally oval or globe shaped.

Seeds of some species are attacked by the caterpillars of Agathiphaga, some of the most primitive of all living moths.

Uses

Kauri logs and loggers near Piha

Various species of kauri give diverse resins such as kauri gum. The timber is generally straight-grained and of fine quality with an exceptional strength-to-weight ratio and rot resistance, making it ideal for yacht hull construction. The wood is commonly used in the manufacture of guitars and ukuleles due to its low density and relatively low price of production. It is also used for some Go boards (goban). The uses of the New Zealand species (A. australis) included shipbuilding, house construction, wood panelling, furniture making, mine braces, and railway sleepers. Due to the hard resin of the wood, it was the traditionally preferred material used by Māori for wooden weapons, patu aruhe (fernroot beaters) and barkcloth beaters.

Evolutionary history

Within Araucariaceae, Agathis is more closely related to Wollemia than to Araucaria. The oldest fossils currently confidently assignable to Agathis are those of Agathis immortalis from the Salamanca Formation of Patagonia, which dates to the Paleocene, approximately 64.67–63.49 million years ago. Agathis-like leaves are also known from the slightly older Lefipán Formation of the same region, which date to the very end of the Cretaceous. Other fossils of the genus are known from the Eocene of Patagonia, the Late Paleocene-Miocene of southern Australia, and the Oligocene-Miocene of New Zealand. Agathis-like remains are also found in the older Bahariya Formation of Egypt.

Species list

Phylogeny of Agathis
section

A. australis (Don) Lindley

Rostrata
section

A. atropurpurea Hyland

A. microstachya Bailey & White

A. dammara (Lamb.) Richard & Richard

A. robusta (Moore ex von Mueller) Bailey

A. labillardieri Warburg

A. borneensis Warburg

A. philippinensis Warburg

A. vitiensis (Seemann) Bentham & Hooker ex Drake

A. macrophylla (Lindley 1851) Masters

A. silbae de Laubenfels

A. corbassonii de Laubenfels

A. lanceolata Lindl. ex Warburg

A. ovata (Moore ex Vieillard) Warburg

A. moorei (Lindley) Masters

A. montana de Laubenfels

Agathis
Accepted species
Image Scientific name Common Name Distribution
Agathis atropurpurea black kauri, blue kauri Queensland, Australia
Agathis australis New Zealand kauri North Island, New Zealand
Agathis borneensis Borneo kauri western Malesia, Borneo
Agathis dammara Sulawesi kauri Philippines, Sulawesi, Maluku Islands
Agathis flavescens Tahan Agathis Peninsular Malaysia
Agathis kinabaluensis Kinabalu kauri Borneo
Agathis labillardieri New Guinea kauri New Guinea
Agathis lanceolata Koghi kauri New Caledonia
Agathis lenticula Sabah kauri Borneo
Agathis macrophylla (syn. A. vitiensis) Pacific kauri, dakua Fiji, Vanuatu, Solomon Islands
Agathis microstachya bull kauri Queensland, Australia
Agathis montana New Caledonia
Agathis moorei white kauri New Caledonia
Agathis orbicula Sarawak kauri Borneo
Agathis ovata Scrub kauri New Caledonia
Agathis robusta Queensland kauri Queensland, Australia; Papua New Guinea
Agathis robusta subsp. robusta Queensland and Papua New Guinea
Agathis robusta subsp. nesophila New Guinea kauri Papua New Guinea
Agathis silbae Vanuatu
Agathis zamunerae Patagonia, South America Argentina
Formerly included

Moved to Nageia

  1. Agathis motleyi - Nageia motleyi
  2. Agathis veitchii - Nageia nagi

The placement of the fossil species "Agathis" jurassica from the Late Jurassic of Australia in this genus is doubtful.

Gallery


This page was last updated at 2024-03-21 11:40 UTC. Update now. View original page.

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