''Agathis'', commonly known as kauri or dammara, is a genus of 22 species of evergreen tree. The genus is part of the ancient

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

family Araucariaceae, a group once widespread during the Jurassic and Cretaceous periods, but now largely restricted to the Southern Hemisphere except for a number of

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

Malesian ''Agathis''.de Laubenfels, David J. 1988. Coniferales. P. 337–453 in Flora Malesiana, Series I, Vol. 10. Dordrecht: Kluwer Academic.

Description

Mature kauri trees have characteristically large trunks, with little or no branching below the crown. In contrast, young trees are normally

conical A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines conn ...

in shape, forming a more rounded or irregularly shaped crown as they achieve maturity.Whitmore, T.C. 1977. ''A first look at Agathis''. Tropical Forestry Papers No. 11. University of Oxford

Commonwealth Forestry Institute The Department of Plant Sciences, at the University of Oxford, England, was a former Oxford department that researched plant and fungal biology. It was part of the university's Mathematical, Physical and Life Sciences Division. From 1 August 2 ...

. The

bark Bark may refer to: * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Places * Bark, Germany * Bark, Warmian-Masurian Voivodeship, Poland Arts, ...

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 A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

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 Elliptical may mean: * having the shape of an ellipse, or more broadly, any oval shape ** in botany, having an elliptic leaf shape ** of aircraft wings, having an elliptical planform * characterised by ellipsis (the omission of words), or by conc ...

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 Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...

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

caterpillar Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder Sym ...

s of '' Agathiphaga'', some of the most primitive of all living moths.

Uses

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 Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the C ...

for wooden weapons, patu aruhe (fernroot beaters) and barkcloth beaters.

Evolutionary history

Within Araucariaceae, Agathis is more closely related to '' Wollemia'' than to ''

Araucaria ''Araucaria'' (; original pronunciation: .ɾawˈka. ɾja is a genus of evergreen Conifer, coniferous trees in the family Araucariaceae. There are 20 extant taxon, extant species in New Caledonia (where 14 species are endemism, ende ...

.'' 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 The Lefipán Formation is a Maastrichtian to Danian, straddling the Cretaceous-Paleogene boundary, geologic formation of the Cañadón Asfalto Basin in Chubut Province, Patagonia, Argentina. The up to thick stratigraphic unit comprises mudstones ...

of the same region, which date to the very end of the Cretaceous.

Species list

;Accepted species ;Formerly included Moved to '' Nageia'' # ''Agathis motleyi -

Nageia motleyi ''Nageia motleyi'' is a species of conifer in the family Podocarpaceae. It is found in Brunei, Indonesia, Malaysia, and Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Sout ...

'' # ''Agathis veitchii - Nageia nagi''

Gallery

File:'Lord of the Forest' Tane Mahuta.jpg, Tāne Mahuta, an '' Agathis australis'' in Waipoua Forest, the largest tree in New Zealand by volume File:Te Matua Ngahere.jpg, Te Matua Ngahere, an ''A. australis'' in Waipoua Forest, the oldest (and 2nd largest) tree in New Zealand File:Yakas kauri tree trunk 2.jpg, Trunk of the Yakas kauri (7th largest) File:Agathis lanceolata.jpg, ''Agathis lanceolata'' File:Agathis ovata 2.jpg, ''Agathis ovata'' File:AgathisMacroCones.jpg, ''Agathis macrophylla'' File:Agathisrobusta.JPG, ''Agathis robusta'' File:Agathis borneensis - feuilles.JPG, ''Agathis borneensis'' File:KauriFruchtstand.jpg, '' Agathis australis'' male pollen cone File:KauriSamen.jpg, alt=Agathis australis chaff (seed is small and winged), '' Agathis australis'' seed File:Kauricone01.jpg, '' Agathis australis'' cone File:Agathis australis foliage and cones.jpg, '' Agathis australis'' leaves and cones

References

External links

Systematics of ''Agathis''

Kauri forest
in '' Te Ara: The Encyclopedia of New Zealand''
Threatened Conifers of the World
{{Taxonbar, from=Q216113 Conifer genera