Agathis robusta grows achieved as evergreen tree, the growth heights up to 50 feet with trunk diameters of up to 180 centimeters. The upright trunk of a mature tree is knotless to more than half; the tree crown is dense. The bark of the trunk is orange brown to brown or gray-brown; it is scaled very smooth, at most slightly. The inner bark is colorful tinted brown from red and pink to. The secretion of the rind is transparent to slightly milky.
Main branches and side branches are different. The leaves on the main shoots are spirally, while the leaves are arranged more or less arranged alternately along the side branches. The leaves are entire,; The petiole is 3-10 mm long. The linealischen to elliptical leaves are dark green, 5-13 cm long and 1-4 cm wide; they are thick and rigid and have fine longitudinal, more or less parallel leaf veins. The leaves on young trees are oblong - lanceolate, glossy green, 6-7 inches long and 1-2 inches wide.
The seedling has two nearly sessile sessile cotyledons ( cotyledons ) that are oblong to ovate; they are 3 to 4 inches long and 1 to 1.5 cm wide with fine, more or less parallel leaf veins.
Agathis robusta is monoecious getrenntgeschlechtig ( monoecious ). The male cones are short stalked to sessile. They are cylindrical, 4 to 8.5 (rarely to 10) cm long and 0.7 to 0.9 inches wide and contain 600-1300 Mikrosporophyllen, each carrying 2-8 pollen sacs on the underside. The female cones are spherical to cylindrical and about tennis ball size; they are 9 to 15 inches long and 8 to 10.5 inches wide. They carry 340 to 440, cone scales; the centrally seated scales measure 3.4 to 4.1 times from 3.9 to 4.6 centimeters. The seeds are almost heart-shaped and winged. The ripening time is July to September.
The wood of Agathis robusta is white to pale brown, and the kind of Agathis microstachya relatively similar. The density of the wood is 435-480 kg per cubic meter.
- The leaves of the New Zealand kauri tree ( Agathis australis ) are only about half as large.
- The smooth bark and the large male and female cones are helpful to distinguish it from other species of the genus Agathis.
Distribution and location
The home of this type lies in the coastal areas of Queensland, Australia, as well as in eastern Papua New Guinea.
The distribution area in Queensland consists of two disjoint sub- areas:
One area is located in southern Queensland between Tewantin and Maryborough and on the Fraser Island. This region has a humid subtropical climate; in January, the temperatures average 30 to 32 ° C, in July 6 to 8 ° C. Associated the species is here especially with Flindersia schottiana, Pseudoweinmannia lachnocarpa, Brachychiton acerifolius, Backhousia myrtifolia, Flindersia bennettiana and Rhodamnia trinervia.
The other area in North Queensland is located between the Herbert River and the Big Tableland near Cooktown. Here the climate is humid and tropical; the average temperature in January is 30 to 32 ° C, in July 13 to 19 ° C. Associated with the type is particularly Flindersia ifflaiana, Flindersia bourjotiana, Argyrodendron trifoliolatum, Musgravea heterophylla, Pseudoweinmannia lachnocarpa, Brachychiton acerifolius, Backhousia hughesii, Eucalyptus torelliana, light walnut ( Aleurites moluccana ) and Rhodamnia costata.
The annual rainfall in the Australian locations amount to about 1100 to 3500 mm.
The botanist Charles Moore described this species in 1860 under the name Dammara robusta; his description was in a work of Ferdinand Jacob Heinrich von Mueller: Quart. J. Pharm Soc Trans. Victoria, 2, pp. 173 published. The botanist Frederick Manson Bailey presented the type 1883 in Syn Queensl. fl, p 498 under the currently valid taxon Agathis robusta in the genus Agathis.
The population of Papua New Guinea has been partially described as a variety Agathis robusta var nesophila; partly it is also regarded as a separate species Agathis spathulata.
The wood is used in forestry with a rotation period of 50 to 60 years. It is in the core straw-colored to reddish brown, the sapwood is lighter. The wood is used for furniture, musical instruments, drawing instruments and butter dishes, as well as in Bootsinnenbau than plywood and papermaking.
From reports, specimens on the Fraser Island with 255 inches trunk diameter ( at breast height ) are known, but they are long like. The northern Australian population was decimated by massive Fällaktionen; 2002 a copy here with 137 cm stem diameter and plant height of 43 meters at the mountain station was measured Skyrail to Red Peak via Cairns.
Meanwhile, some planted as ornamental trees copies are already as big as the surviving copies of the natural sites. In Yatton Park, Tauranga, New Zealand 191 cm trunk diameter and 32 meters height were measured on a copy.
- Christopher J. Earle: Agathis robusta. In: The Gymnosperm Database. March 20, 2011, accessed on 21 October 2011 ( English).
- Cheers Gordon (ed.): Botanica: The ABC's of plants. 10,000 species in text and image. Könemann Publishing Company, 2003, ISBN 3-8331-1600-5.