Agathis atropurpurea, commonly known as the blue kauri, and occasionally as the black kauri or purple kauri, is a species of conifer in the very ancient plant family Araucariaceae. The family was distributed almost worldwide during the Jurassic and Cretaceous periods, but is now mostly confined to the Southern Hemisphere. This species is Endemism to a small part of northeastern Queensland, Australia.
Description
Agathis atropurpurea is a large
rainforest emergent tree growing up to in height, and a diameter 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, held on very short petioles measuring long. They are lanceolate to elliptic with fine longitudinal veins, and measure up to .
The male Conifer cone are cylindrical and measure up to long by wide, and are held on a peduncle about long. The mature female cones are green, globular, 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 Bernard Hyland, using specimens he collected from the Bellenden Ker Range 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 name
Agathis is from the
Ancient Greek word 'ball of thread', a reference to the appearance of the female cones. The species epithet
atropurpurea is a combination of the
Latin words 'dark', and '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, specifically to the cloudy, high altitude, simple microphyll vine-fern forests that occur on the granite
north and south of
Cairns. 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, the
Lamb Range, the Bellenden Ker Range, and the high ranges of the western Atherton Tablelands.
The blue kauri favours granite and rhyolite soils, and is often associated with species such as Balanops australiana, Ceratopetalum succirubrum, Ceratopetalum virchowii, Doryphora aromatics, Elaeocarpus ferruginiflorus, Flindersia bourjotiana, Syzygium cryptophlebia, Sundacarpus amarus, Trochocarpa bellendenkerensis, Uromyrtus species, and Xanthostemon pubescens.
Conservation
In the state of
Queensland, to which this species is endemic, the blue kauri is officially regarded by the Department of Environment and Science (Queensland) as having no threats and is classified as least concern (LC). 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 (IUCN) has assessed the species as near-threatened (NT), citing invasive species, the existence of Phytophthora cinnamomi in part of the blue kauri's range, and climate change 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
External links
Notes
