''Agathis atropurpurea'', commonly known as the blue kauri, and occasionally as the black kauri or purple kauri, is a species of

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 ...

in the very ancient plant family

Araucariaceae Araucariaceae – also known as araucarians – is an extremely ancient family of coniferous trees. The family achieved its maximum diversity during the Jurassic and Cretaceous periods and the early Cenozoic, when it was distributed almost worldw ...

. The family was distributed almost worldwide during the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

and

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

periods, but is now mostly confined to the Southern hemisphere. This species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to a small part of northeastern

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

Description

''Agathis atropurpurea'' is a large

rainforest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...

emergent tree growing up to in height, and a

diameter In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid for ...

of up to . The trunk is cylindrical and very straight, with smooth to flaky bark that is mottled with dark blue, purple, and almost black patches. In very large trees the bark is brown and it may then be confused with the bull kauri, '' Agathis microstachya'', a species that is both genetically and geographically related. However even large specimens of the blue kauri will usually have some dark patches that enable a positive identification. The branches are more or less horizontal, and the leaf-bearing twigs are pendant. The leaves are opposite and

distichous In botany, phyllotaxis () or phyllotaxy is the arrangement of leaves on a plant stem. Phyllotactic spirals form a distinctive class of patterns in nature. Leaf arrangement The basic arrangements of leaves on a stem are opposite and alternat ...

, held on very short petioles measuring long. They are

lanceolate The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...

elliptic In mathematics, an ellipse is a plane curve surrounding two focal points, such that for all points on the curve, the sum of the two distances to the focal points is a constant. It generalizes a circle, which is the special type of ellipse in ...

with fine longitudinal veins, and measure up to . The male

cones 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 ...

are cylindrical and measure up to long by wide, and are held on a peduncle about long. The mature female cones are green,

globular A globular cluster is a spheroidal conglomeration of stars. Globular clusters are bound together by gravity, with a higher concentration of stars towards their centers. They can contain anywhere from tens of thousands to many millions of member ...

, about in diameter with up to 150 scales. The seeds are tan in colour, around long with wings up to wide.

Taxonomy

This species was first described by the Australian

botanist Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek wo ...

Bernard Hyland Bernard Hyland (Bernard Patrick Matthew Hyland, born 1937), known as Bernie Hyland, is an Australian botanist. He has contributed significantly to the understanding of Australian plants, in particular numerous species of his home and workplace ...

, using specimens he collected from the

Bellenden Ker Range The Bellenden Ker Range, also known as the Wooroonooran Range is a coastal mountain range in Far North Queensland, Australia. Part of the Great Dividing Range it is located between Gordonvale and Babinda. The whole of the range falls within t ...

in 1972. His paper, titled "A revision of the genus Agathis (Araucariaceae) in Australia", was published in 1978 in the journal ''Brunonia'', which is now known as ''Australian Systematic Botany''.

Etymology

The

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

name ''Agathis'' is from the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

word ''ἀγαθίς'', "ball of thread", a reference to the appearance of the female cones. The species epithet ''atropurpurea'' is a combination of the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

words ''āter'', "dark", and ''purpura'', "purple", and refers to the dark blue/purple colour of the bark.

Distribution and habitat

The range of ''Agathis atropurpurea'' is confined to a number of small fragmented populations within the

Wet Tropics of Queensland The Wet Tropics of Queensland World Heritage Site consists of approximately 8,940 km2 of Australian wet tropical forests growing along the north-east Queensland portion of the Great Dividing Range. The Wet Tropics of Queensland meets all f ...

, specifically to the cloudy, high altitude, simple microphyll vine-fern forests that occur on the granite

massif In geology, a massif ( or ) is a section of a planet's crust that is demarcated by faults or flexures. In the movement of the crust, a massif tends to retain its internal structure while being displaced as a whole. The term also refers to a ...

s north and south of

Cairns Cairns (, ) is a city in Queensland, Australia, on the tropical north east coast of Far North Queensland. The population in June 2019 was 153,952, having grown on average 1.02% annually over the preceding five years. The city is the 5th-most-p ...

. These are areas of high rainfall—more than p.a.—at elevations from to , and include places such as Mount Pieter Botte,

Mount Lewis National Park Mount Lewis National Park is national park in both the Shire of Mareeba and Douglas Shire of Far North Queensland, Australia. It is adjacent to both Daintree National Park and Mount Spurgeon National Park. It is part of the Wet Tropics of Queens ...

, the

Lamb Range Lamb Range is a locality in the Cairns Region, Queensland, Australia. In the , Lamb Range had a population of 0. Geography The locality takes its name from the mountain range Lamb Range. The locality that lies to the west of most of the south ...

, the

, and the high ranges of the western

Atherton Tablelands The Atherton Tableland is a fertile plateau which is part of the Great Dividing Range in Queensland, Australia. The principal river flowing across the plateau is the Barron River. It was dammed to form an irrigation reservoir named Lake Tinar ...

. The blue kauri favours

granite Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies undergro ...

and

rhyolite Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...

soils, and is often associated with species such as ''

Balanops australiana ''Balanops'' is a group of flowering plants described as a genus in 1871. The nine species are trees or shrubs, found in New Caledonia, Fiji, Vanuatu, and northern Queensland. They are dioecious, with separate male and female plants. The genus ...

'', ''

Ceratopetalum succirubrum ''Ceratopetalum succirubrum'' is a species of plant in the family Cunoniaceae. It is found in Australia, West Papua (Indonesia), and Papua New Guinea. It is threatened by habitat loss. First collected by botanists at Gadgarra on the Atherton Ta ...

'', ''

Ceratopetalum virchowii ''Ceratopetalum'' is a genus of nine species of shrub and tree in the family Cunoniaceae. They are found along the eastern coast of Australia and extend north to New Guinea. Two Australian species are among the best known, one being '' C. apetal ...

'', '' Doryphora aromatics'', '' Elaeocarpus ferruginiflorus'', '' Flindersia bourjotiana'', '' Syzygium cryptophlebia'', '' Sundacarpus amarus'', '' Trochocarpa bellendenkerensis'', '' Uromyrtus'' species, and '' Xanthostemon pubescens''.

Conservation

In the state of

, to which this species is endemic, the blue kauri is officially regarded by the

Department of Environment and Science (Queensland) The Department of Environment and Science is a department of the Queensland Government which is responsible for protecting the state's natural environment, developing the government's science strategy, and driving the government's policy and pr ...

as having no threats and is classified as

least concern (LC) A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

. Nor is it listed in the Queensland Confidential Species list, which seeks to limit publication of location data for at-risk species. In contrast, the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

(IUCN) has assessed the species as near-threatened (NT), citing

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

, the existence of ''

Phytophthora cinnamomi ''Phytophthora cinnamomi'' is a soil-borne water mould that produces an infection which causes a condition in plants variously called "root rot", "dieback", or (in certain '' Castanea'' species), "ink disease". The plant pathogen is one of the wo ...

'' in part of the blue kauri's range, and

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...

as potential threats to the species. The IUCN notes, however, that no assessment of these potential threats has been conducted, and that the population of the blue kauri is currently stable. Considering that the species is already confined to the highest peaks within its range, the threat of climate change must be considered as real and imminent.

Gallery

File:Agathis atropurpurea trunk Cairns Botanic Gardens January 2021 SF21001.jpg File:Agathis-atropurpurea-SF22355-03.jpg File:Conifer - The black kauri or blue kauri, - Agathis atropurpurea (16082593546).jpg File:Agathis-atropurpurea-SF22355-04.jpg

References

External links

* *
View a map
of historical sightings of ''Agathis atropurpurea'' at the

Australasian Virtual Herbarium The ''Australasian Virtual Herbarium'' (AVH) is an online resource that allows access to plant specimen data held by various Australian and New Zealand herbaria. It is part of the Atlas of Living Australia (ALA), and was formed by the amalgamat ...

View observations
of this species on

iNaturalist iNaturalist is a social network of naturalists, citizen scientists, and biologists built on the concept of mapping and sharing observations of biodiversity across the globe. iNaturalist may be accessed via its website or from its mobile applic ...

See images
of ''Agathis atropurpurea'' on Flickriver

Notes

{{Taxonbar, from=Q2709503 atropurpurea Pinales of Australia Trees of Australia Near threatened flora of Australia Endemic flora of Queensland Least concern biota of Queensland Taxonomy articles created by Polbot Taxa named by Bernard Hyland Plants described in 1978