Agathis Atropurpurea

''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 endemic 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 cones 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 ''ἀγαθίς'' 'ball of thread', a reference to the appearance of the female cones. The species epithet ''atropurpurea'' is a combination of the Latin 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, specifically to the cloudy, high altitude, simple microphyll vine-fern forests that occur on the granite massifs 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

References

External links

View a map
of historical sightings of ''Agathis atropurpurea'' at the Australasian Virtual Herbarium

View observations
of this species on iNaturalist

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