Kauri Pine Bull Kauri, Bull Pine
Agathis microstachya J.F. Bailey & C.T. White
Kauri pine is a medium-sized to tall tree attaining 50 m in height and 2.7 m in diameter. The trunk is not buttressed and is usually straight with little taper until the start of the crown where there is an abrupt change. It is a tree that can attain massive dimensions.
This species has a very limited distribution being almost confined to the Atherton Tableland of northeastern Queensland. It is found mainly in the Atherton to Malanda area where it is regarded as a rare species.
Its occurrence is on gently undulating topography. Soils are usually deep loams to clays on granite, meta-morphics, acid volcanics or basalt.
While kauri pine grows as an emergent over a variety of rainforest habitats, it often occurs in the interzone between closed rainforests and tall open eucalypt forests. It is associated with a large number of tropical rainforest tree species.
Related species: Agathis robusta and Agathis atropurpurea. The female cones of A. microstachya are more than 6 cm in diameter and contain 160-210 scales per cone while the male cones are sessile, less than 3 cm long, with scales somewhat flattened at the apex and fewer than 500 scales per cone. The female cones of A. robusta are more than 8 cm in diameter and contain more than 250 scales per cone (about 340-440) while the male cones are greater than 3 cm long and contain more than 500 scales per cone (about 600-1300). The female cones of A. atropurpurea are less than 6 cm in diameter, containing 90-150 scales per cone, while the male cones are distinctly pedunculate with fewer than 500 scales per cone, the scales being slightly rounded at the apex and tending to overlap. Hyland (1978) revised Agathis in Australia.
Publication: QldDept Agric. Stock Bot. Bull. 18, 14 (1916). Type: Atherton district, northern Queensland,
Names: Botanical—Greek agathis (a ball of thread), an allusion to the globose female cone; Greek micros (small) plus stachys (ear of corn or a flower spike), alluding to the small male strobili. Common—kauri is the Maori word for Agathis australis; pine because it is a conifer.
Bark: Coarsely flaky and brown to grey-brown in colour. The outer blaze is mixed pink and brown; the bark exudate is somewhat milky and has a faint scent (pinene).
Leaves: Cotyledons—2, almost sessile, oblong or ovate, 2.5-3 X 1-1.5 cm, slightly stem-clasping; nervation fine, indistinct, longitudinal, more or less parallel. Seedling— spirally arranged on orthotropic shoots but opposite to subopposite on plagiotropic shoots; leaves on plagiotropic shoots are shortly petiolate (petioles about 0.2 cm long), ovate-lanceolate, acute, 5-8 X 1.5-2.5 cm, with numerous parallel veins, no clear midrib. Adult—as for seedling leaves, petiolate (petioles about 0.1-0.2 cm long), linear to elliptic, 2-9 X 0.52.5 cm, stiff; nervation fine, longitudinal, more or less parallel.
Strobili: Male and female strobili are borne on the same tree. Male strobili are shortly pedunculate to almost sessile,
I.1-1.6 X 0.6-0.8 cm, scales 400-500, each bearing 2-5 pollen sacs on the underside. Strobili mature in December.
Cones: Mature cones are globular to ovoid, 7.5-11.5 X 6.5-10 cm, scales 160-210, those from the equatorial section of the cone 2.6-3.5 X 3.3-4.5 cm being generally glaucous at the apex when fresh. Seeds, excluding the wing, are cordate.
Wood: Sapwood is not susceptible to Lyctus attack; heartwood is cream to pale brown, growth rings usually inconspicuous. The timber is highly regarded, even in texture, stable, easy to work and polishes well, soft, light and the density range is about 525 kg m-3. It is not durable in contact with the ground, but it can be used for veneer, house framing and flooring and also in joinery and allied fields.
Climate: Altitudinal range: 600-1000 m; Hottest/coldest month: 30°C/10°C; Frost incidence: low to moderate (some each year at high elevation sites); Rainfall: 1400-3300 mm per year, summer max.
Distinctive features: Coarsely flaky bark, small male strobili with 400-500 scales, medium-sized cones with 160-210 scales, leaves with numerous fine longitudinal parallel veins.
Agathis microstachya 1. Mature leaves 2. Seedling 3. Female cone 4. Male cones and leaves 5. Male cone 6. Tree butt 7. Tree, Gadgarra State Forest, near Atherton, Qld 8. Close-up of bark 9. Cotyledons on a young seedling
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